Wireless power transmitter and wireless power transfer method thereof in many-to-one communication

ABSTRACT

A wireless power transmitter for transmitting power in a wireless manner by forming a wireless power signal and a wireless power transfer method thereof are capable of optimizing transmission efficiency for a plurality of wireless power receivers, by deciding an optimal transmission parameter (especially, a frequency corresponding to the wireless power signal or a resonant frequency) for the plurality of wireless power receivers based on control errors received from the plurality of wireless power receivers, respectively, via respective time slots allocated to the plurality of wireless power receivers.

RELATED APPLICATION

Pursuant to 35 U.S.C. §119(e), this application claims the benefit ofearlier filing date and right of priority to U.S. ProvisionalApplication No. 61/502,709, filed on Jun. 29, 2011, the contents ofwhich is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to wireless power transfer (contactlesspower transfer), and more particularly, wireless power transferaccording to a charge characteristic.

2. Description of the Related Art

In recent years, the method of contactlessly supplying electrical energyto electronic devices in a wireless manner has been used instead of thetraditional method of supplying electrical energy in a wired manner. Theelectronic device receiving energy in a wireless manner may be directlydriven by the received wireless power, or a battery may be charged byusing the received wireless power, then allowing the electronic deviceto be driven by the charged power.

SUMMARY OF THE INVENTION

In accordance with the embodiments disclosed herein, there is provided awireless power transmitter and a wireless power transferring method, ina wireless power transferring method for a wireless power transmittertransferring power in a wireless manner by forming a wireless powersignal, in which transmission efficiency for a plurality of wirelesspower receivers can be optimized by deciding an optimal transmissionparameter for the plurality of wireless power receivers (especially, afrequency or resonant frequency corresponding to a wireless powersignal) based on a control error received from (or transmitted by) eachof the plurality of wireless power receivers via time slots allocatedthereto.

In an embodiment, there is disclosed a wireless power transfer methodfor a wireless power transmitter which transfers power in a wirelessmanner by forming a wireless power signal, the method includingacquiring control errors corresponding to a plurality of wireless powerreceivers, respectively, detecting transmission parameters correspondingto the plurality of wireless power receivers, respectively, based on theacquired control errors, and transferring power in the wireless mannerto each of the plurality of wireless power receivers by forming thewireless power signal based on the detected transmission parameters.

In one aspect of the present disclosure, the control error correspondingto each of the plurality of wireless power receivers may be generatedbased on at least one of a value obtained by subtracting an actuallyreceived amount of power from a target amount of power corresponding toeach of the plurality of wireless power receivers, a value obtained bysubtracting an actually received receiving side voltage from a targetreceiving side voltage corresponding to each of the plurality ofwireless power receivers, a value obtained by subtracting an actuallyreceived receiving side current from a target receiving side currentcorresponding to each of the plurality of wireless power receivers, avalue obtained by subtracting transmission efficiency upon actuallyreceiving power in a wireless manner from a target transmissionefficiency corresponding to each of the plurality of wireless powerreceivers, and a value obtained by subtracting a transmission gain uponactually receiving power in a wireless manner from a target transmissiongain corresponding to each of the plurality of wireless power receivers.

In one aspect of the present disclosure, the transmission efficiency maybe a ratio between transmission power of the wireless power transmitterand reception power corresponding to each of the plurality of wirelesspower receivers, the transmission gain may be a ratio between atransmitting side voltage corresponding to the wireless powertransmitter and a receiving side voltage corresponding to each of theplurality of wireless power receivers, and the reception power may bedetected based on a receiving side voltage and a receiving side currentcorresponding to each of the plurality of wireless power receivers.

In one aspect of the present disclosure, each of the plurality ofwireless power receivers may transmit a packet including a power controlmessage to the wireless power transmitter, the control error may betransmitted to the wireless power transmitter by being included in thepacket including the power control message, and the packet including thepower control message may be generated by modulating the wireless powersignal by each of the plurality of wireless power receivers.

In one aspect of the present disclosure, the transmission parameter maybe at least one of a frequency, an amplitude and a phase of the wirelesspower signal, and a time interval for transmission of the wireless powersignal.

In one aspect of the present disclosure, the transmission parameter maybe a transmission frequency corresponding to each of the plurality ofwireless power receivers, and the transferring of the power in thewireless manner based on the detected transmission parameters mayinclude periodically changing the frequency of the wireless power signalto a transmission frequency corresponding to each of the plurality ofwireless power receivers, and transferring power in the wireless mannerby forming the wireless power signal using the periodically changedtransmission frequency.

In one aspect of the present disclosure, the transferring of the powerin the wireless manner based on the detected transmission parameters mayinclude detecting an optimal transmission parameter corresponding to theplurality of wireless power receivers based on the detected transmissionparameters, and transferring power in the wireless manner to theplurality of wireless power receivers by forming the wireless powersignal based on the optimal transmission parameter.

In one aspect of the present disclosure, the optimal transmissionparameter may be generated by processing the detected transmissionparameters in a statistical manner.

In one aspect of the present disclosure, the statistical manner may be amethod based on at least one of an average, variance and standarddeviation of the transmission parameters.

In one aspect of the present disclosure, the transmission parameter maybe a transmission frequency corresponding to each of the plurality ofwireless power receivers, and the transferring of the power in thewireless manner based on the detected transmission parameters mayinclude setting a weight for each of the plurality of wireless powerreceivers based on the control errors or the detected transmissionparameters, setting a transmission time interval for each of theplurality of wireless power receivers based on the weights, andtransferring power in the wireless manner by forming the wireless powersignal having the transmission frequency corresponding to each of theplurality of wireless power transmitters for the set transmission timeinterval.

In one aspect of the present disclosure, the weight may be proportionalto the control error corresponding to each of the plurality of wirelesspower receivers.

In one aspect of the present disclosure, the transmission parameter maybe decided such that that the control error of each of the plurality ofwireless power receivers is less than a reference value.

In one aspect of the present disclosure, the transmission parameter maybe decided such that a control error value of a specific wireless powerreceiver of the plurality of wireless power receivers does not increasemore than a specific value.

In one aspect of the present disclosure, the transmission parameter maybe decided based on at least one of whether or not a damage is caused onthe plurality of wireless power receivers (or at least one of theplurality of wireless power receivers) or whether or not the pluralityof wireless power receivers (or at least one of the plurality ofwireless power receivers) are able to wirelessly receive power from thewireless power transmitter.

In one aspect of the present disclosure, the method may further includetransmitting a control error transmission request to each of theplurality of wireless power receivers.

In one aspect of the present disclosure, the control error transmissionrequest may be transmitted when the control error is more than areference value, when a new wireless power receiver is placed in aspecific area, when the number of wireless power receivers existing inthe specific area changes, when a position of at least one wirelesspower receiver existing in the specific area changes, and when there isa periodically received request or a request received from the wirelesspower receiver, and the specific area may be an area through which thewireless power signal passes or an area on which the wireless powerreceiver is sensed.

In one aspect of the present disclosure, each of the plurality ofwireless power receivers may transmit the control error to the wirelesspower transmitter via each time slot corresponding thereto, and the timeslot may be formed by dividing a time section for transmission of thewireless power signal by a time axis so as to be allocated to each ofthe plurality of wireless power receivers.

In one aspect of the present disclosure, the plurality of wireless powerreceivers may include a first wireless power receiver and a secondwireless power receiver. Here, the wireless power transmitter mayacquire a first control error via a time slot corresponding to the firstwireless power receiver, so as to detect a first transmission parametercorresponding to the first wireless power receiver. The wireless powertransmitter may acquire a second control error via a time slotcorresponding to the second wireless power receiver, so as to detect asecond transmission parameter corresponding to the second wireless powerreceiver. The wireless power transmitter may transfer power in thewireless manner to the first and second wireless power receivers byforming the wireless power signal based on the first and secondtransmission parameters.

In accordance with one exemplary embodiment, there is provided awireless power transmitter including a power transmission unitconfigured to transmit a wireless power signal and acquire controlerrors from a plurality of wireless power receivers receiving thewireless power signal, respectively, and a controller configured todetect transmission parameters corresponding to the plurality ofwireless power receivers, respectively, based on the acquired controlerrors, and control the power transmission unit to transmit power in awireless manner to each of the plurality of wireless power receivers byforming the wireless power signal based on the detected transmissionparameters.

In one aspect of the present disclosure, the power transmission unit maysequentially acquire the control errors, which correspond to each of theplurality of wireless power receivers, respectively, from the pluralityof wireless power receivers, respectively, and the controller may detectthe transmission parameters corresponding to the plurality of wirelesspower receivers, respectively, based on the sequentially acquiredcontrol errors, detect an optimal transmission parameter correspondingto the plurality of wireless power receivers based on the detectedtransmission parameters, and control the power transmission unit totransmit power in a wireless manner to the plurality of wireless powerreceivers by forming the wireless power signal based on the optimaltransmission parameter.

In one aspect of the present disclosure, the optimal transmissionparameter may be decided as an average value of the transmissionparameters corresponding to the plurality of wireless power receivers,respectively.

In one aspect of the present disclosure, the control error may begenerated based on a value obtained by subtracting an actually receivedreceiving side voltage from a target receiving side voltagecorresponding to each the plurality of wireless power receivers. Here,each of the plurality of wireless power receivers may transmit a packetto the wireless power transmitter, the packet including informationrelated to the control error, and the packet may be generated bymodulating the wireless power signal by each of the plurality ofwireless power receivers.

In accordance with a wireless power transmitter and a wireless powertransfer method according to exemplary embodiments, transmissionefficiency for a plurality of wireless power receivers can be optimizedby deciding an optimal transmission parameter for the plurality ofwireless power receivers (especially, a frequency corresponding to awireless power signal or a resonant frequency) based on control errorsreceived from (or transmitted by) the plurality of wireless powerreceivers, respectively, via corresponding allocated time slots.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is an exemplary view conceptually illustrating a wireless powertransmitter and an electronic device according to the embodiments of thepresent invention;

FIGS. 2A and 2B are exemplary block diagrams illustrating theconfiguration of a wireless power transmitter 100 and an electronicdevice 200 that can be employed in the embodiments disclosed herein,respectively;

FIG. 3 is a view illustrating a concept in which power is transferredfrom a wireless power transmitter to an electronic device in a wirelessmanner according to an inductive coupling method;

FIGS. 4A and 4B are a block diagram illustrating part of the wirelesspower transmitter 100 and electronic device 200 in a magnetic inductionmethod that can be employed in the embodiments disclosed herein;

FIG. 5 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to an inductive coupling method that can be employed in theembodiments disclosed herein;

FIG. 6 is a view illustrating a concept in which power is transferred toan electronic device from a wireless power transmitter in a wirelessmanner according to a resonance coupling method;

FIGS. 7A and 7B are a block diagram illustrating part of the wirelesspower transmitter 100 and electronic device 200 in a resonance methodthat can be employed in the embodiments disclosed herein;

FIG. 8 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to a resonance coupling method that can be employed in theembodiments disclosed herein;

FIG. 9 is a block diagram illustrating a wireless power transmitterfurther including an additional element in addition to the configurationillustrated in FIG. 2A;

FIG. 10 is view illustrating a configuration in case where an electronicdevice 200 according to the embodiments disclosed herein is implementedin the form of a mobile terminal;

FIGS. 11A and 11B are a view illustrating the concept of transmittingand receiving a packet between a wireless power transmitter and anelectronic device through the modulation and demodulation of a wirelesspower signal in transferring power in a wireless manner disclosedherein;

FIGS. 12A and 12B is a view illustrating a method of showing data bitsand byte constituting a power control message provided by the wirelesspower transmitter 100;

FIG. 13 is a view illustrating a packet including a power controlmessage used in a contactless (wireless) power transfer method accordingto the embodiments disclosed herein;

FIG. 14 is a view illustrating the operation phases of the wirelesspower transmitter 100 and electronic device 200 according to theembodiments disclosed herein;

FIGS. 15 through 19 are views illustrating the structure of packetsincluding a power control message between the wireless power transmitter100 and electronic device 200;

FIG. 20A is a view illustrating a wireless power transfer method basedon a control error in a many-to-one communication;

FIG. 20B is an exemplary view illustrating the wireless power transfermethod in the many-to-one communication;

FIG. 21 is a block diagram illustrating the configuration of a wirelesspower transmitter in accordance with exemplary embodiments;

FIG. 22 is an exemplary embodiment illustrating a method for requestingand obtaining a control error in a wireless power transmitter inaccordance with one exemplary embodiment;

FIG. 23 is a flowchart illustrating a wireless power transfer method inaccordance with exemplary embodiments;

FIG. 24 is a flowchart illustrating a wireless power transfer method (ora wireless power control method) in accordance with a first exemplaryembodiment;

FIG. 25 is an exemplary view illustrating the wireless power transfermethod in accordance with the first exemplary embodiment;

FIG. 26 is a flowchart illustrating a wireless power transfer method inaccordance with a second exemplary embodiment;

FIG. 27 is an exemplary view illustrating the wireless power transfermethod in accordance with the second exemplary embodiment;

FIG. 28 is a flowchart illustrating a wireless power transfer method inaccordance with a third exemplary embodiment;

FIG. 29 is an exemplary view illustrating the wireless power transfermethod in accordance with the third exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The technologies disclosed herein may be applicable to wireless powertransfer (contactless power transfer). However, the technologiesdisclosed herein are not limited to this, and may be also applicable toall kinds of power transmission systems and methods, wireless chargingcircuits and methods to which the technological spirit of the technologycan be applicable, in addition to the methods and apparatuses usingpower transmitted in a wireless manner.

It should be noted that technological terms used herein are merely usedto describe a specific embodiment, but not to limit the presentinvention. Also, unless particularly defined otherwise, technologicalterms used herein should be construed as a meaning that is generallyunderstood by those having ordinary skill in the art to which theinvention pertains, and should not be construed too broadly or toonarrowly. Furthermore, if technological terms used herein are wrongterms unable to correctly express the spirit of the invention, then theyshould be replaced by technological terms that are properly understoodby those skilled in the art. In addition, general terms used in thisinvention should be construed based on the definition of dictionary, orthe context, and should not be construed too broadly or too narrowly.

Incidentally, unless clearly used otherwise, expressions in the singularnumber include a plural meaning. In this application, the terms“comprising” and “including” should not be construed to necessarilyinclude all of the elements or steps disclosed herein, and should beconstrued not to include some of the elements or steps thereof, orshould be construed to further include additional elements or steps.

In addition, a suffix “module” or “unit” used for constituent elementsdisclosed in the following description is merely intended for easydescription of the specification, and the suffix itself does not giveany special meaning or function.

Furthermore, the terms including an ordinal number such as first,second, etc. can be used to describe various elements, but the elementsshould not be limited by those terms. The terms are used merely for thepurpose to distinguish an element from the other element. For example, afirst element may be named to a second element, and similarly, a secondelement may be named to a first element without departing from the scopeof right of the invention.

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings, and thesame or similar elements are designated with the same numeral referencesregardless of the numerals in the drawings and their redundantdescription will be omitted.

In describing the present invention, moreover, the detailed descriptionwill be omitted when a specific description for publicly knowntechnologies to which the invention pertains is judged to obscure thegist of the present invention. Also, it should be noted that theaccompanying drawings are merely illustrated to easily explain thespirit of the invention, and therefore, they should not be construed tolimit the spirit of the invention by the accompanying drawings.

FIG. 1—Conceptual View of Wireless Power Transmitter and ElectronicDevice

FIG. 1 is an exemplary view conceptually illustrating a wireless powertransmitter and an electronic device according to the embodiments of thepresent invention.

Referring to FIG. 1, the wireless power transmitter 100 may be a powertransfer apparatus configured to transfer power required for theelectronic device 200 in a wireless manner.

Furthermore, the wireless power transmitter 100 may be a wirelesscharging apparatus configured to charge a battery of the electronicdevice 200 by transferring power in a wireless manner. A case where thewireless power transmitter 100 is a wireless charging apparatus will bedescribed later with reference to FIG. 9.

Additionally, the wireless power transmitter 100 may be implemented withvarious forms of apparatuses transferring power to the electronic device200 requiring power in a contactless state.

The electronic device 200 is a device that is operable by receivingpower from the wireless power transmitter 100 in a wireless manner.Furthermore, the electronic device 200 may charge a battery using thereceived wireless power.

On the other hand, an electronic device for receiving power in awireless manner as described herein should be construed broadly toinclude a portable phone, a cellular phone, a smart phone, a personaldigital assistant (PDA), a portable multimedia player (PMP), a tablet, amultimedia device, or the like, in addition to an input/output devicesuch as a keyboard, a mouse, an audio-visual auxiliary device, and thelike.

The electronic device 200, as described later, may be a mobilecommunication terminal, (for example, a portable phone, a cellularphone, and a tablet or multimedia device). In case where the electronicdevice is a mobile terminal, it will be described later with referenceto FIG. 10.

On the other hand, the wireless power transmitter 100 may transfer powerin a wireless manner without mutual contact to the electronic device 200using one or more wireless power transfer methods. In other words, thewireless power transmitter 100 may transfer power using at least one ofan inductive coupling method based on magnetic induction phenomenon bythe wireless power signal and a magnetic resonance coupling method basedon electromagnetic resonance phenomenon by a wireless power signal at aspecific frequency.

Wireless power transfer in the inductive coupling method is a technologytransferring power in a wireless manner using a primary coil and asecondary coil, and refers to the transmission of power by inducing acurrent from a coil to another coil through a changing magnetic field bya magnetic induction phenomenon.

Wireless power transfer in the inductive coupling method refers to atechnology in which the electronic device 200 generates resonance by awireless power signal transmitted from the wireless power transmitter100 to transfer power from the wireless power transmitter 100 to thewireless power receiver 200 by the resonance phenomenon.

Hereinafter, the wireless power transmitter 100 and electronic device200 according to the embodiments disclosed herein will be described indetail. In assigning reference numerals to the constituent elements ineach of the following drawings, the same reference numerals will be usedfor the same constituent elements even though they are shown in adifferent drawing.

FIGS. 2A and 2B are an exemplary block diagrams illustrating theconfiguration of a wireless power transmitter 100 and an electronicdevice 200 that can be employed in the embodiments disclosed herein.

FIG. 2A—Wireless Power Transmitter

Referring to FIG. 2A, the wireless power transmitter 100 may include apower transmission unit 110. The power transmission unit 110 may includea power conversion unit 111 and a power transmission control unit 112.

The power conversion unit 111 transfers power supplied from atransmission side power supply unit 190 to the electronic device 200 byconverting it into a wireless power signal. The wireless power signaltransferred by the power conversion unit 111 is generated in the form ofa magnetic field or electromagnetic field having an oscillationcharacteristic. For this purpose, the power conversion unit 111 may beconfigured to include a coil for generating the wireless power signal.

The power conversion unit 111 may include a constituent element forgenerating a different type of wireless power signal according to eachpower transfer method.

In accordance with exemplary embodiments, the power conversion unit 111may include a primary coil for forming a changing magnetic field toinduce a current to a secondary coil of the electronic device 200.Furthermore, the power conversion unit 111 may include a coil (orantenna) for forming a magnetic field having a specific resonantfrequency to generate a resonant frequency in the electronic device 200according to the resonance coupling method.

Furthermore, the power conversion unit 111 may transfer power using atleast one of the foregoing inductive coupling method and the resonancecoupling method.

Among the constituent elements included in the power conversion unit111, those for the inductive coupling method will be described laterwith reference to FIGS. 4 and 5, and those for the resonance couplingmethod will be described with reference to FIGS. 7 and 8.

On the other hand, the power conversion unit 111 may further include acircuit for controlling the characteristics of a used frequency, anapplied voltage, an applied current or the like to form the wirelesspower signal.

The power transmission control unit 112 controls each of the constituentelements included in the power transmission unit 110 The powertransmission control unit 112 may be implemented to be integrated intoanother control unit (not shown) for controlling the wireless powertransmitter 100.

On the other hand, a region to which the wireless power signal can beapproached may be divided into two types. First, an active area denotesa region through which a wireless power signal transferring power to theelectronic device 200 is passed. Next, a semi-active area denotes aninterest region in which the wireless power transmitter 100 can detectthe existence of the electronic device 200. Here, the power transmissioncontrol unit 112 may detect whether the electronic device 200 is placedin the active area or detection area or removed from the area.Specifically, the power transmission control unit 112 may detect whetheror not the electronic device 200 is placed in the active area ordetection area using a wireless power signal formed from the powerconversion unit 111 or a sensor separately provided therein. Forinstance, the power transmission control unit 112 may detect thepresence of the electronic device 200 by monitoring whether or not thecharacteristic of power for forming the wireless power signal is changedby the wireless power signal, which is affected by the electronic device200 existing in the detection area. However, the active area anddetection area may vary according to the wireless power transfer methodsuch as an inductive coupling method, a resonance coupling method, andthe like.

The power transmission control unit 112 may perform the process ofidentifying the electronic device 200 or determine whether to startwireless power transfer according to a result of detecting the existenceof the electronic device 200.

Furthermore, the power transmission control unit 112 may determine atleast one characteristic of a frequency, a voltage, and a current of thepower conversion unit 111 for forming the wireless power signal. Thedetermination of the characteristic may be carried out by a condition atthe side of the wireless power transmitter 100 or a condition at theside of the electronic device 200. In exemplary embodiments, the powertransmission control unit 112 may decide the characteristic based ondevice identification information. In another exemplary embodiment, thepower transmission control unit 112 may decide the characteristic basedon required power information of the electronic device 200 or profileinformation related to the required power. The power transmissioncontrol unit 112 may receive a power control message from the electronicdevice 200. The power transmission control unit 112 may determine atleast one characteristic of a frequency, a voltage and a current of thepower conversion unit 111 based on the received power control message,and additionally perform other control operations based on the powercontrol message.

For example, the power transmission control unit 112 may determine atleast one characteristic of a frequency, a voltage and a current used toform the wireless power signal according to the power control messageincluding at least one of rectified power amount information, chargingstate information and identification information in the electronicdevice 200.

Furthermore, as another control operation using the power controlmessage, the wireless power transmitter 100 may perform a typicalcontrol operation associated with wireless power transfer based on thepower control message. For example, the wireless power transmitter 100may receive information associated with the electronic device 200 to beauditorily or visually outputted through the power control message, orreceive information required for authentication between devices.

In exemplary embodiments, the power transmission control unit 112 mayreceive the power control message through the wireless power signal. Inother exemplary embodiment, the power transmission control unit 112 mayreceive the power control message through a method for receiving userdata.

In order to receive the foregoing power control message, the wirelesspower transmitter 100 may further include a modulation/demodulation unit113 electrically connected to the power conversion unit 111. Themodulation/demodulation unit 113 may modulate a wireless power signalthat has been modulated by the electronic device 200 and use it toreceive the power control message. The method for allowing the powerconversion unit 111 to receive a power control message using a wirelesspower signal will be described later with reference to FIGS. 11 through13.

In addition, the power transmission control unit 112 may acquire a powercontrol message by receiving user data including a power control messageby a communication means (not shown) included in the wireless powertransmitter 100.

In accordance with one exemplary embodiment, the wireless powertransmitter 100 may supply power to a plurality of electronic devices.Here, collision may occur between wireless power signal which have beenmodulated by the plurality of electronic devices. Hence, the constituentelements included in the wireless power transmitter 100 may performvarious operations to avoid such collision between the modulatedwireless power signal.

In one exemplary embodiment, the power conversion unit 111 may convertpower supplied from the transmission side power supply unit 190 into awireless power signal and transfer it to the plurality of electronicdevices. For example, the plurality of electronic devices may be twoelectronic devices, namely, a first electronic device and a secondelectronic device.

The power conversion unit 111 may generate a wireless power signal forpower transmission, and receive a first response signal and a secondresponse signal corresponding to the wireless power signal.

The power transmission control unit 112 may determine whether or not thefirst and second response signals collide with each other. When thefirst and second response signals collide with each other according tothe determination result, the power transmission control unit 112 mayreset the power transmission.

The first and second response signals may be generated by modulating thewireless power signal through the first and second electronic devices.

Through the resetting of the power transmission, the power transmissioncontrol unit 112 may control the power conversion unit 111 tosequentially receive the first and second response signals, which aregenerated to avoid collision with each other.

The sequential reception indicates that the first response signal isreceived after a first time interval and the second response signal isreceived after a second time interval within a predetermined responseperiod. The first and second time intervals may be decided based on avalue obtained by generating a random number.

The predetermined response period (Tping interval) may be decided to belong enough to include both the first response signal and the secondresponse signal. Also, it may be decided after resetting the powertransmission.

In accordance with one exemplary embodiment, occurrence ornon-occurrence of the collision may be determined according to whetheror not the first and second response signals are decoded using a presetformat. The preset format may include a preamble, a header and amessage. Whether or not the first and second response signals collidewith each other may be determined based on whether or not the first andsecond response signals are not recoverable due to an error generationin at least one of the preamble, the header and the message caused bythe collision.

In accordance with one exemplary embodiment, the power conversion unit111 may periodically receive a response signal of the first device,which does not collide with a response signal of the second devicewithin a first response period (Tping interval_1). The powertransmission control unit may decode the first response signal and thesecond response signal using a preset format, and determine whether ornot the first and second response signals have collided with each otherbased on whether or not the decoding is performed. Here, the firstresponse signal and the second response signal may be periodicallyreceived within a second response period (Tping interval_2). The secondresponse period (Tping interval_2) may be decided long enough to includeboth the first and second response signals, and be decided afterresetting the power transmission.

FIG. 2B—Electronic Device

Referring to FIG. 2B, the electronic device 200 may include a powersupply unit 290. The power supply unit 290 supplies power required forthe operation of the electronic device 200. The power supply unit 290may include a power receiving unit 291 and a Power reception controlunit (or POWER RECEIVING CONTROL UNIT) 292.

The power receiving unit 291 receives power transferred from thewireless power transmitter 100 in a wireless manner.

The power receiving unit 291 may include constituent elements requiredto receive the wireless power signal according to a wireless powertransfer method. Furthermore, the power receiving unit 291 may receivepower according to at least one wireless power transfer method, and inthis case, the power receiving unit 291 may include constituent elementsrequired for each method.

First, the power receiving unit 291 may include a coil for receiving awireless power signal transferred in the form of a magnetic field orelectromagnetic field having a vibration characteristic.

For instance, as a constituent element according to the inductivecoupling method, the power receiving unit 291 may include a secondarycoil to which a current is induced by a changing magnetic field. Inexemplary embodiments, the power receiving unit 291, as a constituentelement according to the resonance coupling method, may include a coiland a resonant circuit in which resonance phenomenon is generated by amagnetic field having a specific resonant frequency.

In another exemplary embodiments, when the power receiving unit 291receives power according to at least one wireless power transfer method,the power receiving unit 291 may be implemented to receive power byusing a coil, or implemented to receive power by using a coil formeddifferently according to each power transfer method.

Among the constituent elements included in the power receiving unit 291,those for the inductive coupling method will be described later withreference to FIGS. 4A and 4B, and those for the resonance couplingmethod with reference to FIGS. 7A and 7B.

On the other hand, the power receiving unit 291 may further include arectifier and a regulator to convert the wireless power signal into adirect current. Furthermore, the power receiving unit 291 may furtherinclude a circuit for protecting an overvoltage or overcurrent frombeing generated by the received power signal.

The Power reception control unit (or POWER RECEIVING CONTROL UNIT) 292may control each constituent element included in the power supply unit290.

Specifically, the Power reception control unit (or POWER RECEIVINGCONTROL UNIT) 292 may transfer a power control message to the wirelesspower transmitter 100. The power control message may instruct thewireless power transmitter 100 to initiate or terminate a transfer ofthe wireless power signal. Furthermore, the power control message mayinstruct the wireless power transmitter 100 to control a characteristicof the wireless power signal.

In exemplary embodiments, the Power reception control unit (or POWERRECEIVING CONTROL UNIT) 292 may transmit the power control messagethrough the wireless power signal. In another exemplary embodiment, thePower reception control unit (or POWER RECEIVING CONTROL UNIT) 292 maytransmit the power control message through a method for transmittinguser data.

In order to transmit the foregoing power control message, the electronicdevice 200 may further include a modulation/demodulation unit 293electrically connected to the power receiving unit 291. Themodulation/demodulation unit 293, similarly to the case of the wirelesspower transmitter 100, may be used to transmit the power control messagethrough the wireless power signal. The power communicationsmodulation/demodulation unit 293 may be used as a means for controllinga current and/or voltage flowing through the power conversion unit 111of the wireless power transmitter 100. Hereinafter, a method forallowing the power communications modulation/demodulation unit 113 or293 at the side of the wireless power transmitter 100 and at the side ofthe electronic device 200, respectively, to be used to transmit andreceive a power control message through a wireless power signal will bedescribed.

A wireless power signal formed by the power conversion unit 111 isreceived by the power receiving unit 291. At this time, the Powerreception control unit (or POWER RECEIVING CONTROL UNIT) 292 controlsthe power communications modulation/demodulation unit 293 at the side ofthe electronic device 200 to modulate the wireless power signal. Forinstance, the Power reception control unit (or POWER RECEIVING CONTROLUNIT) 292 may perform a modulation process such that a power amountreceived from the wireless power signal is varied by changing areactance of the power communications modulation/demodulation unit 293connected to the power receiving unit 291. The change of a power amountreceived from the wireless power signal results in the change of acurrent and/or voltage of the power conversion unit 111 for forming thewireless power signal. At this time, the modulation/demodulation unit113 at the side of the wireless power transmitter 100 may detect achange of the current and/or voltage to perform a demodulation process.

In other words, the Power reception control unit (or POWER RECEIVINGCONTROL UNIT) 292 may generate a packet including a power controlmessage intended to be transferred to the wireless power transmitter 100and modulate the wireless power signal to allow the packet to beincluded therein, and the power transmission control unit 112 may decodethe packet based on a result of performing the demodulation process ofthe power communications modulation/demodulation unit 113 to acquire thepower control message included in the packet. The detailed method ofallowing the wireless power transmitter 100 to acquire the power controlmessage will be described later with reference to FIGS. 11 through 13.

In addition, the Power reception control unit (or POWER RECEIVINGCONTROL UNIT) 292 may transmit a power control message to the wirelesspower transmitter 100 by transmitting user data including the powercontrol message by a communication means (not shown) included in theelectronic device 200.

In addition, the power supply unit 290 may further include a charger 298and a battery 299.

The electronic device 200 receiving power for operation from the powersupply unit 290 may be operated by power transferred from the wirelesspower transmitter 100, or operated by charging the battery 299 using thetransferred power and then receiving the charged power. At this time,the Power reception control unit (or POWER RECEIVING CONTROL UNIT) 292may control the charger 298 to perform charging using the transferredpower.

In one exemplary embodiment, the plurality of electronic devices mayreceive power from the wireless power transmitter 100. Here, collisionmay occur between wireless power signal which have been modulated by theplurality of electronic devices. Hence, the constituent elementsincluded in the wireless power transmitter 100 may perform variousoperations to avoid such collision between the modulated wireless powersignal.

In one exemplary embodiment, the power receiving unit 291 may receivethe wireless power signal for the power transmission from the wirelesspower transmitter.

Here, the Power reception control unit (or POWER RECEIVING CONTROL UNIT)292 may control the power receiving unit 291 to transmit a thirdresponse signal corresponding to the wireless power signal after a timeinterval set to a first time within the first response period (Tpinginterval_1).

In one exemplary embodiment, the Power reception control unit (or POWERRECEIVING CONTROL UNIT) 292 may determine whether or not the powertransmission of the wireless power transmitter 100 has been reset due tocollision between the modulated wireless power signal, and set the timeinterval to a second time when the power transmission has been resetaccording to the determination result.

In one exemplary embodiment, the Power reception control unit (or POWERRECEIVING CONTROL UNIT) 292 may control the power receiving unit 291 totransmit a fourth response signal corresponding to the wireless powersignal after the time interval set to the second time within the secondresponse period (Tping interval_2). The second time may be decided by avalue obtained by generating a random number. Hereinafter, a wirelesspower transmitter and an electronic device applicable to the embodimentsdisclosed herein will be described.

First, a method of allowing the wireless power transmitter to transferpower to the electronic device according to the inductive couplingmethod will be described with reference to FIGS. 3 through 5.

FIG. 3—Inductive Coupling Method

FIG. 3 is a view illustrating a concept in which power is transferredfrom a wireless power transmitter to an electronic device in a wirelessmanner according to an inductive coupling method.

When the power of the wireless power transmitter 100 is transferred inan inductive coupling method, if the strength of a current flowingthrough a primary coil within the power transmission unit 110 ischanged, then a magnetic field passing through the primary coil will bechanged by the current. The changed magnetic field generates an inducedelectromotive force at a secondary coil in the electronic device 200.

According to the foregoing method, the power conversion unit 111 of thewireless power transmitter 100 may include a transmitting (Tx) coil 1111a being operated as a primary coil in magnetic induction. Furthermore,the power receiving unit 291 of the electronic device 200 may include areceiving (Rx) coil 2911 a being operated as a secondary coil inmagnetic induction.

First, the wireless power transmitter 100 and electronic device 200 aredisposed in such a manner that the transmitting coil 1111 a at the sideof the wireless power transmitter 100 and the receiving coil at the sideof the electronic device 200 are located adjacent to each other. Then,if the power transmission control unit 112 controls a current of thetransmitting coil 1111 a to be changed, then the power receiving unit291 controls power to be supplied to the electronic device 200 using anelectromotive force induced to the receiving coil 2911 a.

The efficiency of wireless power transfer by the inductive couplingmethod may be little affected by a frequency characteristic, butaffected by an alignment and distance between the wireless powertransmitter 100 and the electronic device 200 including each coil.

On the other hand, in order to perform wireless power transfer in theinductive coupling method, the wireless power transmitter 100 may beconfigured to include an interface surface (not shown) in the form of aflat surface. One or more electronic devices may be placed at an upperportion of the interface surface, and the transmitting coil 1111 a maybe mounted at a lower portion of the interface surface. In this case, avertical spacing is formed in a small-scale between the transmittingcoil 1111 a mounted at a lower portion of the interface surface and thereceiving coil 2911 a of the electronic device 200 placed at an upperportion of the interface surface, and thus a distance between the coilsbecomes sufficiently small to efficiently implement contactless powertransfer by the inductive coupling method.

Furthermore, an alignment indicator (not shown) indicating a locationwhere the electronic device 200 is to be placed at an upper portion ofthe interface surface. The alignment indicator indicates a location ofthe electronic device 200 where an alignment between the transmittingcoil 1111 a mounted at a lower portion of the interface surface and thereceiving coil 2911 a can be suitably implemented. The alignmentindicator may alternatively be simple marks, or may be formed in theform of a protrusion structure for guiding the location of theelectronic device 200. Otherwise, the alignment indicator may be formedin the form of a magnetic body such as a magnet mounted at a lowerportion of the interface surface, thereby guiding the coils to besuitably arranged by mutual magnetism to a magnetic body having anopposite polarity mounted within the electronic device 200.

On the other hand, the wireless power transmitter 100 may be formed toinclude one or more transmitting coils. The wireless power transmitter100 may selectively use some of coils suitably arranged with thereceiving coil 2911 a of the electronic device 200 among the one or moretransmitting coils to enhance the power transmission efficiency. Thewireless power transmitter 100 including the one or more transmittingcoils will be described later with reference to FIG. 5.

Hereinafter, a configuration of the wireless power transmitter andelectronic device using an inductive coupling method applicable to theembodiments disclosed herein will be described in detail.

FIGS. 4A and 4B—Wireless Power Transmitter and Electronic Device inInductive Coupling Method

FIGS. 4A and 4B are a block diagram illustrating part of the wirelesspower transmitter 100 and electronic device 200 in a magnetic inductionmethod that can be employed in the embodiments disclosed herein. Aconfiguration of the power transmission unit 110 included in thewireless power transmitter 100 will be described with reference to FIG.4A, and a configuration of the power supply unit 290 included in theelectronic device 200 will be described with reference to FIG. 4B.

Referring to FIG. 4A, the power conversion unit 111 of the wirelesspower transmitter 100 may include a transmitting (Tx) coil 1111 a and aninverter 1112.

The transmitting coil 1111 a may form a magnetic field corresponding tothe wireless power signal according to a change of current as describedabove. The transmitting coil 1111 a may alternatively be implementedwith a planar spiral type or cylindrical solenoid type.

The inverter 1112 transforms a DC input obtained from the power supplyunit 190 into an AC waveform. The AC current transformed by the inverter1112 drives a resonant circuit including the transmitting coil 1111 aand a capacitor (not shown) to form a magnetic field in the transmittingcoil 1111 a.

In addition, the power conversion unit 111 may further include apositioning unit 1114.

The positioning unit 1114 may move or rotate the transmitting coil 1111a to enhance the effectiveness of contactless power transfer using theinductive coupling method. As described above, it is because analignment and distance between the wireless power transmitter 100 andthe electronic device 200 including a primary coil and a secondary coilmay affect power transfer using the inductive coupling method. Inparticular, the positioning unit 1114 may be used when the electronicdevice 200 does not exist within an active area of the wireless powertransmitter 100.

Accordingly, the positioning unit 1114 may include a drive unit (notshown) for moving the transmitting coil 1111 a such that acenter-to-center distance of the transmitting coil 1111 a of thewireless power transmitter 100 and the receiving coil 2911 a of theelectronic device 200 is within a predetermined range, or rotating thetransmitting coil 1111 a such that the centers of the transmitting coil1111 a and the receiving coil 2911 a are overlapped with each other.

For this purpose, the wireless power transmitter 100 may further includea detection unit (not shown) made of a sensor for detecting the locationof the electronic device 200, and the power transmission control unit112 may control the positioning unit 1114 based on the locationinformation of the electronic device 200 received from the locationdetection sensor.

Furthermore, to this end, the power transmission control unit 112 mayreceive control information on an alignment or distance to theelectronic device 200 through the power communicationsmodulation/demodulation unit 113, and control the positioning unit 1114based on the received control information on the alignment or distance.

If the power conversion unit 111 is configured to include a plurality oftransmitting coils, then the positioning unit 1114 may determine whichone of the plurality of transmitting coils is to be used for powertransmission. The configuration of the wireless power transmitter 100including the plurality of transmitting coils will be described laterwith reference to FIG. 5.

On the other hand, the power conversion unit 111 may further include apower sensing unit 1115. The power sensing unit 1115 at the side of thewireless power transmitter 100 monitors a current or voltage flowinginto the transmitting coil 1111 a. The power sensing unit 1115 isprovided to check whether or not the wireless power transmitter 100 isnormally operated, and thus the power sensing unit 1115 may detect avoltage or current of the power supplied from the outside, and checkwhether the detected voltage or current exceeds a threshold value. Thepower sensing unit 1115, although not shown, may include a resistor fordetecting a voltage or current of the power supplied from the outsideand a comparator for comparing a voltage value or current value of thedetected power with a threshold value to output the comparison result.Based on the check result of the power sensing unit 1115, the powertransmission control unit 112 may control a switching unit (not shown)to cut off power applied to the transmitting coil 1111 a.

Referring to FIG. 4B, the power supply unit 290 of the electronic device200 may include a receiving (Rx) coil 2911 a and a rectifier generationcircuit 2913.

A current is induced into the receiving coil 2911 a by a change of themagnetic field formed in the transmitting coil 1111 a. Theimplementation type of the receiving coil 2911 a may be a planar spiraltype or cylindrical solenoid type similarly to the transmitting coil1111 a.

Furthermore, series and parallel capacitors may be configured to beconnected to the receiving coil 2911 a to enhance the effectiveness ofwireless power reception or perform resonant detection.

The receiving coil 2911 a may be in the form of a single coil or aplurality of coils.

The rectifier generation circuit 2913 performs a full-wave rectificationto a current to convert alternating current into direct current. Therectifier generation circuit 2913, for instance, may be implemented witha full-bridge rectifier generation circuit made of four diodes or acircuit using active components.

In addition, the rectifier generation circuit 2913 may further include aregulator circuit for converting a rectified current into a more flatand stable direct current. Furthermore, the output power of therectifier generation circuit 2913 is supplied to each constituentelement of the power supply unit 290. Furthermore, the rectifiergeneration circuit 2913 may further include a DC-DC converter forconverting output DC power into a suitable voltage to adjust it to thepower required for each constituent element (for instance, a circuitsuch as a charger 298).

The power communications modulation/demodulation unit 293 may beconnected to the power receiving unit 291, and may be configured with aresistive element in which resistance varies with respect to directcurrent, and may be configured with a capacitive element in whichreactance varies with respect to alternating current. The Powerreception control unit (or POWER RECEIVING CONTROL UNIT) 292 may changethe resistance or reactance of the power communicationsmodulation/demodulation unit 293 to modulate a wireless power signalreceived to the power receiving unit 291.

On the other hand, the power supply unit 290 may further include a powersensing unit 2914. The power sensing unit 2914 at the side of theelectronic device 200 monitors a voltage and/or current of the powerrectified by the rectifier generation circuit 2913, and if the voltageand/or current of the rectified power exceeds a threshold value as aresult of monitoring, then the Power reception control unit (or POWERRECEIVING CONTROL UNIT) 292 transmits a power control message to thewireless power transmitter 100 to transfer suitable power.

FIG. 5—Wireless Power Transmitter Configured to Include One or MoreTransmitting Coils

FIG. 5 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to an inductive coupling method that can be employed in theembodiments disclosed herein.

Referring to FIG. 5, the power conversion unit 111 of the wireless powertransmitter 100 according to the embodiments disclosed herein mayinclude one or more transmitting coils 1111 a-1 to 1111 a-n. The one ormore transmitting coils 1111 a-1 to 1111 a-n may be an array of partlyoverlapping primary coils. An active area may be determined by some ofthe one or more transmitting coils.

The one or more transmitting coils 1111 a-1 to 1111 a-n may be mountedat a lower portion of the interface surface. Furthermore, the powerconversion unit 111 may further include a multiplexer 1113 forestablishing and releasing the connection of some of the one or moretransmitting coils 1111 a-1 to 1111 a-n.

Upon detecting the location of the electronic device 200 placed at anupper portion of the interface surface, the power transmission controlunit 112 may take the detected location of the electronic device 200into consideration to control the multiplexer 1113, thereby allowingcoils that can be placed in an inductive coupling relation to thereceiving coil 2911 a of the electronic device 200 among the one or moretransmitting coils 1111 a-1 to 1111 a-n to be connected to one another.

For this purpose, the power transmission control unit 112 may acquirethe location information of the electronic device 200. For example, thepower transmission control unit 112 may acquire the location of theelectronic device 200 on the interface surface by the location detectionunit (not shown) provided in the wireless power transmitter 100. Foranother example, the power transmission control unit 112 mayalternatively receive a power control message indicating a strength ofthe wireless power signal from an object on the interface surface or apower control message indicating the identification information of theobject using the one or more transmitting coils 1111 a-1 to 1111 a-n,respectively, and determines whether it is located adjacent to which oneof the one or more transmitting coils based on the received result,thereby acquiring the location information of the electronic device 200.

On the other hand, the active area as part of the interface surface maydenote a portion through which a magnetic field with a high efficiencycan pass when the wireless power transmitter 100 transfers power to theelectronic device 200 in a wireless manner. At this time, a singletransmitting coil or one or a combination of more transmitting coilsforming a magnetic field passing through the active area may bedesignated as a primary cell. Accordingly, the power transmissioncontrol unit 112 may determine an active area based on the detectedlocation of the electronic device 200, and establish the connection of aprimary cell corresponding to the active area to control the multiplexer1113, thereby allowing the receiving coil 2911 a of the electronicdevice 200 and the coils belonging to the primary cell to be placed inan inductive coupling relation.

In the meantime, upon disposing one or more electronic devices 200 on aninterface surface of the wireless power transmitter 100, which includesthe one or more transmitting coils 1111 a-1 to 1111 a-n, the powertransmission control unit 112 may control the multiplexer 1113 to allowthe coils belonging to the primary cell corresponding to the position ofeach electronic device to be placed in the inductive coupling relation.Accordingly, the wireless power transmitter 100 may generate thewireless power signal using different coils, thereby transferring it tothe one or more electronic devices in a wireless manner.

Also, the power transmission control unit 112 may set power having adifferent characteristic to be supplied to each of the coilscorresponding to the electronic devices. Here, the wireless powertransmitter 100 may transfer power by differently setting a powertransfer scheme, efficiency, characteristic and the like for eachelectronic device. The power transmission for one or more electronicdevices will be described later with reference to FIG. 28.

Furthermore, the power conversion unit 111 may further include animpedance matching unit (not shown) for controlling an impedance to forma resonant circuit with the coils connected thereto.

Hereinafter, a method for allowing a wireless power transmitter totransfer power according to a resonance coupling method will bedisclosed with reference to FIGS. 6 through 8.

FIG. 6—Resonance Coupling Method

FIG. 6 is a view illustrating a concept in which power is transferred toan electronic device from a wireless power transmitter in a wirelessmanner according to an resonance coupling method.

First, resonance will be described in brief as follows. Resonance refersto a phenomenon in which an amplitude of vibration is remarkablyincreased when periodically receiving an external force having the samefrequency as the natural frequency of a vibration system. Resonance is aphenomenon occurring at all kinds of vibrations such as mechanicalvibration, electric vibration, and the like. Generally, when exerting avibratory force to a vibration system from the outside, if the naturalfrequency thereof is the same as a frequency of the externally appliedforce, then the vibration becomes strong, thus increasing the width.

With the same principle, when a plurality of vibrating bodies separatedfrom one another within a predetermined distance vibrate at the samefrequency, the plurality of vibrating bodies resonate with one another,and in this case, resulting in a reduced resistance between theplurality of vibrating bodies. In an electrical circuit, a resonantcircuit can be made by using an inductor and a capacitor.

When the wireless power transmitter 100 transfers power according to theinductive coupling method, a magnetic field having a specific vibrationfrequency is formed by alternating current power in the powertransmission unit 110. If a resonance phenomenon occurs in theelectronic device 200 by the formed magnetic field, then power isgenerated by the resonance phenomenon in the electronic device 200.

Describing a principle of the resonance coupling, in general, a methodfor transferring power by generating an electromagnetic wave exhibitslow power transmission efficiency, and may badly affect human bodies dueto radiation of the electromagnetic waves and exposure to theelectromagnetic waves.

However, if the plurality of vibrating bodies resonate with each otherin an electromagnetic manner as aforementioned, extremely high powertransmission efficiency may be exhibited due to non affection byadjacent objects except for the vibrating bodies. An energy tunnel maybe generated between the plurality of vibrating bodies which resonatewith each other in the electromagnetic manner. This may be referred toas energy coupling or energy tail.

The resonance coupling disclosed herein may use an electromagnetic wavehaving a low frequency. When power is transferred using theelectromagnetic wave having the low frequency, only a magnetic field mayaffect an area located within a single wavelength of the electromagneticwave. The magnetic resonance may be generated when the wireless powertransmitter 100 and the electronic device 200 are located within thesingle wavelength of the electromagnetic wave having the low frequency.

Here, in general, human bodies are sensitive to an electric field buttolerant to a magnetic field. Hence, when power is transferred using amagnetic resonance, the human bodies may be badly affected due to beingexposed to the electromagnetic wave. Also, as the energy tail isgenerated in response to the resonance phenomenon, the form of powertransmission may exhibit a non-radiative property. Consequently, upontransferring power using such electromagnetic wave, a radiative problemwhich occurs frequently may be solved.

The resonance coupling method may be a method for transferring powerusing the electromagnetic wave with the low frequency, asaforementioned. Thus, the transmitting coil 1111 b of the wireless powertransmitter 100 may form a magnetic field or electromagnetic wave fortransferring power in principle. However, the resonance coupling methodwill be described hereinafter from the perspective of a magneticresonance, namely, a power transmission by a magnetic field.

The resonant frequency may be determined by the following formula inEquation 1.

$\begin{matrix}{f = \frac{1}{2\pi\sqrt{LC}}} & \lbrack {{Equation}\mspace{14mu} 1} \rbrack\end{matrix}$

Here, the resonant frequency (f) is determined by an inductance (L) anda capacitance (C) in a circuit. In a circuit forming a magnetic fieldusing a coil, the inductance can be determined by a number of turns ofthe coil, and the like, and the capacitance can be determined by a gapbetween the coils, an area, and the like. In addition to the coil, acapacitive resonant circuit may be configured to be connected thereto todetermine the resonant frequency.

Referring to FIG. 6, when power is transmitted in a wireless manneraccording to the resonance coupling method, the power conversion unit111 of the wireless power transmitter 100 may include a transmitting(Tx) coil 1111 b in which a magnetic field is formed and a resonantcircuit (or RESONANT GENERATION CIRCUIT) 1116 connected to thetransmitting coil 1111 b to determine a specific vibration frequency.The resonant circuit (or RESONANT GENERATION CIRCUIT) 1116 may beimplemented by using a capacitive circuit (capacitors), and the specificvibration frequency may be determined based on an inductance of thetransmitting coil 1111 b and a capacitance of the resonant circuit (orRESONANT GENERATION CIRCUIT) 1116.

The configuration of a circuit element of the resonant circuit (orRESONANT GENERATION CIRCUIT) 1116 may be implemented in various formssuch that the power conversion unit 111 forms a magnetic field, and isnot limited to a form of being connected in parallel to the transmittingcoil 1111 b as illustrated in FIG. 6.

Furthermore, the power receiving unit 291 of the electronic device 200may include a resonant circuit 2912 and a receiving (Rx) coil 2911 b togenerate a resonance phenomenon by a magnetic field formed in thewireless power transmitter 100. In other words, the resonant circuit2912 may be also implemented by using a capacitive circuit, and theresonant circuit 2912 is configured such that a resonant frequencydetermined based on an inductance of the receiving coil 2911 b and acapacitance of the resonant circuit 2912 has the same frequency as aresonant frequency of the formed magnetic field.

The configuration of a circuit element of the resonant circuit 2912 maybe implemented in various forms such that the power receiving unit 291generates resonance by a magnetic field, and is not limited to a form ofbeing connected in series to the receiving coil 2911 b as illustrated inFIG. 6.

The specific vibration frequency in the wireless power transmitter 100may have L_(TX), C_(TX), and may be acquired by using the Equation 1.Here, the electronic device 200 generates resonance when a result ofsubstituting the L_(RX) and C_(RX) of the electronic device 200 to theEquation 1 is same as the specific vibration frequency.

According to a contactless power transfer method by resonance coupling,when the wireless power transmitter 100 and electronic device 200resonate at the same frequency, respectively, an electromagnetic wave ispropagated through a short-range magnetic field, and thus there existsno energy transfer between the devices if they have differentfrequencies.

As a result, an efficiency of contactless power transfer by theresonance coupling method is greatly affected by a frequencycharacteristic, whereas the effect of an alignment and distance betweenthe wireless power transmitter 100 and the electronic device 200including each coil is relatively smaller than the inductive couplingmethod.

Hereinafter, the configuration of a wireless power transmitter and anelectronic device in the resonance coupling method applicable to theembodiments disclosed herein will be described in detail.

FIGS. 7A and 7B—Wireless Power Transmitter in Resonance Coupling Method

FIGS. 7A and 7B is a block diagram illustrating part of the wirelesspower transmitter 100 and electronic device 200 in a resonance methodthat can be employed in the embodiments disclosed herein.

A configuration of the power transmission unit 110 included in thewireless power transmitter 100 will be described with reference to FIG.7A.

The power conversion unit 111 of the wireless power transmitter 100 mayinclude a transmitting (Tx) coil 1111 b, an inverter 1112, and aresonant circuit (or RESONANT GENERATION CIRCUIT) 1116. The inverter1112 may be configured to be connected to the transmitting coil 1111 band the resonant circuit (or RESONANT GENERATION CIRCUIT) 1116.

The transmitting coil 1111 b may be mounted separately from thetransmitting coil 1111 a for transferring power according to theinductive coupling method, but may transfer power in the inductivecoupling method and resonance coupling method using one single coil.

The transmitting coil 1111 b, as described above, forms a magnetic fieldfor transferring power. The transmitting coil 1111 b and the resonantcircuit (or RESONANT GENERATION CIRCUIT) 1116 generate resonance whenalternating current power is applied thereto, and at this time, avibration frequency may be determined based on an inductance of thetransmitting coil 1111 b and a capacitance of the resonant circuit (orRESONANT GENERATION CIRCUIT) 1116.

For this purpose, the inverter 1112 transforms a DC input obtained fromthe power supply unit 190 into an AC waveform, and the transformed ACcurrent is applied to the transmitting coil 1111 b and the resonantcircuit (or RESONANT GENERATION CIRCUIT) 1116.

In addition, the power conversion unit 111 may further include afrequency adjustment unit 1117 for changing a resonant frequency of thepower conversion unit 111. The resonant frequency of the powerconversion unit 111 is determined based on an inductance and/orcapacitance within a circuit constituting the power conversion unit 111by Equation 1, and thus the power transmission control unit 112 maydetermine the resonant frequency of the power conversion unit 111 bycontrolling the frequency adjustment unit 1117 to change the inductanceand/or capacitance.

The frequency adjustment unit 1117, for example, may be configured toinclude a motor for adjusting a distance between capacitors included inthe resonant circuit (or RESONANT GENERATION CIRCUIT) 1116 to change acapacitance, or include a motor for adjusting a number of turns ordiameter of the transmitting coil 1111 b to change an inductance, orinclude active elements for determining the capacitance and/orinductance

On the other hand, the power conversion unit 111 may further include apower sensing unit 1115. The operation of the power sensing unit 1115 isthe same as the foregoing description.

Referring to FIG. 7B, a configuration of the power supply unit 290included in the electronic device 200 will be described. The powersupply unit 290, as described above, may include the receiving (Rx) coil2911 b and resonant circuit 2912.

In addition, the power receiving unit 291 of the power supply unit 290may further include a rectifier generation circuit 2913 for convertingan AC current generated by resonance phenomenon into DC. The rectifiergeneration circuit 2913 may be configured similarly to the foregoingdescription.

Furthermore, the power receiving unit 291 may further include a powersensing unit 2914 for monitoring a voltage and/or current of therectified power. The power sensing unit 2914 may be configured similarlyto the foregoing description.

FIG. 8—Wireless Power Transmitter Configured to Include One or MoreTransmitting Coils

FIG. 8 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to an resonance coupling method that can be employed in theembodiments disclosed herein.

Referring to FIG. 8, the power conversion unit 111 of the wireless powertransmitter 100 according to the embodiments disclosed herein mayinclude one or more transmitting coils 1111 b-1 to 1111 b-n and resonantcircuits (1116-1 to 1116-n) connected to each transmitting coils.Furthermore, the power conversion unit 111 may further include amultiplexer 1113 for establishing and releasing the connection of someof the one or more transmitting coils 1111 b-1 to 1111 b-n.

The one or more transmitting coils 1111 b-1 to 1111 b-n may beconfigured to have the same vibration frequency, or some of them may beconfigured to have different vibration frequencies. It is determined byan inductance and/or capacitance of the resonant circuits (1116-1 to1116-n) connected to the one or more transmitting coils 1111 b-1 to 1111b-n, respectively.

In the meantime, when one or more electronic devices 200 are disposed inan active area or a detection area of the wireless power transmitter 100including the one or more transmitting coils 1111 b-1 to 1111 b-n, thepower transmission control unit 112 may control the multiplexer 1113 toallow the electronic devices to be placed in different resonancecoupling relations. Accordingly, the wireless power transmitter 100 maywirelessly transfer power to the one or more electronic devices bygenerating the wireless power signal using different coils.

In addition, the power transmission control unit 112 may set power witha different characteristic to be supplied to each of the coilscorresponding to the electronic devices. Here, the wireless powertransmitter 100 may transfer power by differently setting a powertransmission scheme, a resonant frequency, efficiency, a characteristicand the like for each electronic device. The power transmission for oneor more electronic devices will be described later with reference toFIG. 28. For this purpose, the frequency adjustment unit 1117 may beconfigured to change an inductance and/or capacitance of the resonantcircuits (1116-1 to 1116-n) connected to the one or more transmittingcoils 1111 b-1 to 1111 b-n, respectively.

FIG. 9—Wireless Power Transmitter Implemented by Charger

On the other hand, hereinafter, an example of the wireless powertransmitter implemented in the form of a wireless charger will bedescribed.

FIG. 9 is a block diagram illustrating a wireless power transmitterfurther including an additional element in addition to the configurationillustrated in FIG. 2A.

Referring to FIG. 9, the wireless power transmitter 100 may furtherinclude a sensor unit 120, a communication unit 130, an output unit 140,a memory 150, and a control unit (or Controller) 180 in addition to thepower transmission unit 110 and power supply unit 190 for supporting atleast one of the foregoing inductive coupling method and resonancecoupling method.

The control unit (or Controller) 180 controls the power transmissionunit 110, the sensor unit 120, the communication unit 130, the outputunit 140, the memory 150, and the power supply unit 190.

The control unit (or Controller) 180 may be implemented by a moduleseparated from the power transmission control unit 112 in the powertransmission unit 110 described with reference to FIG. 2 or may beimplemented by a single module.

The sensor unit 120 may include a sensor for detecting the location ofthe electronic device 200. The location information detected by thesensor unit 120 may be used for allowing the power transmission unit 110to transfer power in an efficient manner.

For instance, in case of wireless power transfer according to theinductive coupling method, the sensor unit 120 may be operated as adetection unit, and the location information detected by the sensor unit120 may be used to move or rotate the transmitting coil 1111 a in thepower transmission unit 110.

Furthermore, for example, the wireless power transmitter 100 configuredto include the foregoing one or more transmitting coils may determinecoils that can be placed in an inductive coupling relation or resonancecoupling relation to the receiving coil of the electronic device 200among the one or more transmitting coils based on the locationinformation of the electronic device 200.

On the other hand, the sensor unit 120 may be configured to monitorwhether or not the electronic device 200 approaches a chargeable region.The approach or non-approach detection function of the sensor unit 120may be carried out separately from the function of allowing the powertransmission control unit 112 in the power transmission unit 110 todetect the approach or non-approach of the electronic device 200.

The communication unit 130 performs wired or wireless data communicationwith the electronic device 200. The communication unit 130 may includean electronic component for at least any one of Bluetooth™, Zigbee,Ultra Wide Band (UWB), Wireless USB, Near Field Communication (NFC), andWireless LAN.

The output unit 140 may include at least one of a display unit 141 andan audio output unit (or SOUND OUTPUT UNIT) 142. The display unit 141may include at least one of a liquid crystal display (LCD), a thin filmtransistor-liquid crystal display (TFT-LCD), an organic light-emittingdiode (OLED), a flexible display, and a three-dimensional (3D) display.The display unit 141 may display a charging state under the control ofthe control unit (or Controller) 180.

The memory 150 may include at least one storage medium of a flash memorytype, a hard disk type, a multimedia card micro type, a card type memory(e.g., SD or XD memory), a random access memory (RAM), a static randomaccess memory (SRAM), a read-only memory (ROM), an electrically erasableprogrammable read-only memory (EEPROM), a programmable read-only memory(PROM), a magnetic memory, a magnetic disk, an optical disk, and thelike. The wireless power transmitter 100 may operate in association witha web storage performing the storage function of the memory 150 on theInternet. A program or commands performing the foregoing functions ofthe wireless power transmitter 100 may be stored in the memory 150. Thecontrol unit (or Controller) 180 may perform the program or commandsstored in the memory 150 to transmit power in a wireless manner. Amemory controller (not shown) may be used to allow other constituentelements (e.g., control unit (or Controller) 180) included in thewireless power transmitter 100 to access the memory 150.

However, it would be easily understood by those skilled in the art thatthe configuration of a wireless power transmitter according to theembodiment disclosed herein may be applicable to an apparatus, such as adocking station, a terminal cradle device, and an electronic device, andthe like, excluding a case where it is applicable to only a wirelesscharger.

FIG. 10—Wireless Power Receiver Implemented with Mobile Terminal

FIG. 10 is view illustrating a configuration in case where an electronicdevice 200 according to the embodiments disclosed herein is implementedin the form of a mobile terminal.

The mobile communication terminal 200 may include a power supply unit290 illustrated in FIG. 2, 4, or 7.

Furthermore, the terminal 200 may further include a wirelesscommunication unit 210, an Audio/Video (NV) input unit 220, a user inputunit 230, a sensing unit 240, an output unit 250, a memory 260, aninterface unit 270, and a controller 280. FIG. 10 illustrates theterminal 100 having various components, but it is understood thatimplementing all of the illustrated components is not a requirement.Greater or fewer components may alternatively be implemented.

Hereinafter, each component is described in sequence.

The wireless communication unit 210 may typically include one or moremodules which permit wireless communications between the terminal 200and a wireless communication system or between the terminal 200 and anetwork within which the terminal 200 is located. For example, thewireless communication unit 210 may include a broadcast receiving module211, a mobile communication module 212, a wireless internet module 213,a short-range communication module 214, a position location module 215and the like.

The broadcast receiving module 211 receives a broadcast signal and/orbroadcast associated information from an external broadcast managingentity via a broadcast channel.

The broadcast channel may include a satellite channel and a terrestrialchannel. The broadcast center may indicate a server which generates andtransmits a broadcast signal and/or broadcast associated information ora server which receives a pre-generated broadcast signal and/orbroadcast associated information and sends them to the portableterminal. The broadcast signal may be implemented as a TV broadcastsignal, a radio broadcast signal, and a data broadcast signal, amongothers. The broadcast signal may further include a data broadcast signalcombined with a TV or radio broadcast signal.

Examples of broadcast associated information may denote informationassociated with a broadcast channel, a broadcast program, a broadcastservice provider, and the like. The broadcast associated information maybe provided via a mobile communication network. In this case, it may bereceived by the mobile communication module 212.

The broadcast associated information may be implemented in variousformats. For instance, broadcast associated information may includeElectronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB),Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld(DVB-H), and the like.

The broadcast receiving module 211 may be configured to receive digitalbroadcast signals transmitted from various types of broadcast systems.Such broadcast systems may include Digital MultimediaBroadcasting-Terrestrial (DMB-T), Digital MultimediaBroadcasting-Satellite (DMB-S), Media Forward Link Only (MediaFLO),Digital Video Broadcast-Handheld (DVB-H), Integrated Services DigitalBroadcast-Terrestrial (ISDB-T) and the like. The broadcast receivingmodule 211 may be configured to be suitable for every broadcast systemtransmitting broadcast signals as well as the digital broadcastingsystems.

Broadcast signals and/or broadcast associated information received viathe broadcast receiving module 211 may be stored in a suitable device,such as a memory 260.

The mobile communication module 212 transmits/receives wireless signalsto/from at least any one of a base station, an external portableterminal, and a server on a mobile communication network. The wirelesssignal may include audio call signal, video (telephony) call signal, orvarious formats of data according to transmission/reception oftext/multimedia messages.

The wireless internet module 213 supports wireless Internet access forthe mobile terminal 200. This module may be internally or externallycoupled to the terminal 100. Examples of such wireless Internet accessmay include Wireless LAN (WLAN) (Wi-Fi), Wireless Broadband (Wibro),Worldwide Interoperability for Microwave Access (Wimax), High SpeedDownlink Packet Access (HSDPA) and the like.

The short-range communication module 214 denotes a module forshort-range communications. Suitable technologies for implementing thismodule may include Bluetooth, Radio Frequency IDentification (RFID),Infrared Data Association (IrDA), Ultra-WideBand (UWB), ZigBee, and thelike. On the other hand, Universal Serial Bus (USB), IEEE 1394,Thunderbolt of Intel technology, and the like, may be used for wiredshort-range communication.

The wireless internet module 213 or the short-range communication module214 may establish data communication connection to the wireless powertransmitter 100.

Through the established data communication, when there is an audiosignal to be outputted while transferring power in a wireless manner,the wireless internet module 213 or the short-range communication module214 may transmit the audio signal to the wireless power transmitter 100through the short-range communication module. Furthermore, through theestablished data communication, when there is information to bedisplayed, the wireless internet module 213 or the short-rangecommunication module 214 may transmit the information to the wirelesspower transmitter 100. Otherwise, the wireless internet module 213 orthe short-range communication module 214 may transmit an audio signalreceived through a microphone integrated in the wireless powertransmitter 100. Furthermore, the wireless internet module 213 or theshort-range communication module 214 may transmit the identificationinformation (e.g., phone number or device name in case of a portablephone) of the mobile terminal 200 to the wireless power transmitter 100through the established data communication.

The position location module 215 is a module for acquiring a position ofthe terminal. An example of the position location module 215 may includea Global Position System (GPS) module.

Referring to FIG. 10, the NV input unit 220 is configured to provideaudio or video signal input to the portable terminal. The A/V input unit220 may include a camera 221 and a microphone 222. The camera 221processes image frames of still or moving images obtained by an imagesensor in a video call mode or a capture more. The processed imageframes may be displayed on the display unit 251.

The image frames processed by the camera 221 may be stored in the memory260 or transmitted to the exterior via the wireless communication unit210. Two or more cameras 221 may be provided therein according to theuse environment.

The microphone 222 may receive an external audio signal by a microphonein a phone call mode, a recording mode, a voice recognition mode, or thelike to process it into electrical audio data. The processed audio datais converted and outputted into a format transmittable to a mobilecommunication base station via the mobile communication module 212 incase of the phone call mode. The microphone 222 may include variousnoise removal algorithms to remove noises generated while receiving theexternal audio signal.

The user input unit 230 may generate input data to allow the user tocontrol the operation of the terminal. The user input unit 230 mayinclude a keypad, a dome switch, a touchpad (e.g., staticpressure/capacitance), a jog wheel, a jog switch and the like.

The sensing unit 240 may include a proximity sensor 241, a pressuresensor 242, a motion sensor 243, and the like. The proximity sensor 241detects an object approaching the mobile terminal 200, or the presenceor absence of an object existing adjacent to the mobile terminal 200,and the like without any mechanical contact. The proximity sensor 241may detect a proximity object using a change of the AC magnetic field orstatic magnetic field, a change rate of the electrostatic capacity, orthe like. Two or more proximity sensors 241 may be provided according tothe aspect of configuration.

The pressure sensor 242 may detect whether or not a pressure is appliedto the mobile terminal 200, a size of the pressure, and the like. Thepressure sensor 242 may be provided at a portion where the detection ofa pressure is required in the mobile terminal 200 according to the useenvironment. When the pressure sensor 242 is provided in the displayunit 251, it may be possible to identify a touch input through thedisplay unit 251 and a pressure touch input by which a pressure largerthan the touch input is applied according to a signal outputted from thepressure sensor 242. Furthermore, it may be possible to know a size ofthe pressure applied to the display unit 251 during the input of apressure touch.

The motion sensor 243 detects the location or movement of the mobileterminal 200 using an acceleration sensor, a gyro sensor, and the like.The acceleration sensor used in the motion sensor 243 is an element forconverting an acceleration change in any one direction into anelectrical signal. Two or three axes are typically integrated into apackage to constitute an acceleration sensor, and only one Z-axis may berequired according to the use environment. Accordingly, when anacceleration sensor in the direction of X-axis or Y-axis should be usedinstead of the direction of Z-axis due to any reason, the accelerationsensor may be erected and mounted on a main substrate using a separatepiece substrate. Furthermore, the gyro sensor is a sensor for measuringan angular speed of the mobile terminal 200 in a rotational movement todetect a rotated angle with respect to each reference direction. Forinstance, the gyro sensor may detect each rotational angle, i.e.,azimuth, pitch and roll, with reference to three directional axes.

The output unit 250 is provided to output visual, auditory, or tactileinformation. The output unit 250 may include a display unit 251, anaudio output module 252, an alarm unit 253, a haptic module 254, and thelike.

The display unit 251 may display (output) information processed in theterminal 200. For example, when the terminal is in a phone call mode,the display unit 251 will provide a User Interface (UI) or Graphic UserInterface (GUI) associated with the call. When the terminal is in avideo call mode or a capture mode, the display unit 251 may displayimages captured and/or received, UI, or GUI.

The display unit 251 may include at least one of a liquid crystaldisplay (LCD), a thin film transistor-liquid crystal display (TFT-LCD),an organic light-emitting diode (OLED), a flexible display, athree-dimensional (3D) display, and the like.

Some of those displays may be configured as a transparent type or anlight transmission type through which the outside is visible, which isreferred to as a transparent display. A representative example of thetransparent display may include a Transparent OLED (TOLED), or the like.The rear surface of the display unit 151 may also be implemented to beoptically transparent. Under this configuration, the user can view anobject positioned at a rear side of the terminal body through a regionoccupied by the display unit 251 of the terminal body.

The display unit 251 may be implemented in two or more in numberaccording to a configured aspect of the terminal 200. For instance, aplurality of the display units 251 may be arranged on one surface to bespaced apart from or integrated with each other, or may be arranged ondifferent surfaces.

Here, if the display unit 251 and a touch sensitive sensor (referred toas a touch sensor) have a layered structure therebetween, the displayunit 251 may be used as an input device rather than an output device.The touch sensor may be implemented as a touch film, a touch sheet, atouch pad, and the like.

The touch sensor may be configured to convert changes of a pressureapplied to a specific part of the display unit 251, or a capacitanceoccurring from a specific part of the display unit 251, into electricinput signals. Also, the touch sensor may be configured to sense notonly a touched position and a touched area, but also a touch pressure.

When touch inputs are sensed by the touch sensors, corresponding signalsare sent to a touch controller. The touch controller processes thereceived signals, and then transmits corresponding data to thecontroller 280. Accordingly, the controller 280 may sense which regionof the display unit 151 has been touched.

The proximity sensor 241 may be arranged at an inner region of theterminal covered by the touch screen, or near the touch screen. Theproximity sensor refers to a sensor to sense the presence or absence ofan object approaching a surface to be sensed, or an object disposed neara surface to be sensed, using an electromagnetic field or infrared rayswithout a mechanical contact. The proximity sensor has a longer lifespanand a more enhanced utility than a contact sensor.

The proximity sensor may include a transmissive type photoelectricsensor, a direct reflective type photoelectric sensor, a mirrorreflective type photoelectric sensor, a high-frequency oscillationproximity sensor, a capacitance type proximity sensor, a magnetic typeproximity sensor, an infrared rays proximity sensor, and so on. When thetouch screen is implemented as a capacitance type, proximity of apointer to the touch screen is sensed by changes of an electromagneticfield. In this case, the touch screen (touch sensor) may be categorizedinto a proximity sensor.

Hereinafter, for the sake of brief explanation, a status that thepointer is positioned to be proximate onto the touch screen withoutcontact will be referred to as a “proximity touch”, whereas a statusthat the pointer substantially comes in contact with the touch screenwill be referred to as a “contact touch”. For the position correspondingto the proximity touch of the pointer on the touch screen, such positioncorresponds to a position where the pointer faces perpendicular to thetouch screen upon the proximity touch of the pointer.

The proximity sensor senses proximity touch, and proximity touchpatterns (e.g., distance, direction, speed, time, position, movingstatus, etc.). Information relating to the sensed proximity touch andthe sensed proximity touch patterns may be output onto the touch screen.

The audio output module 252 may output audio data received from thewireless communication unit 210 or stored in the memory 260, in acall-receiving mode, a call-placing mode, a recording mode, a voicerecognition mode, a broadcast reception mode, and so on. The audiooutput module 252 may output audio signals relating to functionsperformed in the terminal 200, e.g., sound alarming a call received or amessage received, and so on. The audio output module 252 may include areceiver, a speaker, a buzzer, and so on.

The alarm 253 outputs signals notifying the occurrence of an event fromthe terminal 200. The event occurring from the terminal 100 may includecall received, message received, key signal input, touch input, and soon. The alarm 253 may output not only video or audio signals, but alsoother types of signals such as signals notifying occurrence of events ina vibration manner. Since the video or audio signals can be outputthrough the display unit 251 or the audio output unit 252, the displayunit 251 and the audio output module 252 may be categorized into part ofthe alarm 253.

The haptic module 254 generates various tactile effects which a user canfeel. A representative example of the tactile effects generated by thehaptic module 254 includes vibration. Vibration generated by the hapticmodule 254 may have a controllable intensity, a controllable pattern,and so on. For instance, different vibration may be output in asynthesized manner or in a sequential manner.

The haptic module 254 may generate various tactile effects, includingnot only vibration, but also arrangement of pins vertically moving withrespect to a skin being contacted, air injection force or air suctionforce through an injection hole or a suction hole, touch by a skinsurface, presence or absence of contact with an electrode, effects bystimulus such as an electrostatic force, reproduction of cold or hotfeeling using a heat absorbing device or a heat emitting device, and thelike.

The haptic module 254 may be configured to transmit tactile effectsthrough the user's direct contact, or the user's muscular sense using afinger or a hand. The haptic module 254 may be implemented in two ormore in number according to the configuration of the terminal 200.

The memory 260 may store a program for the processing and control of thecontroller 280. Alternatively, the memory 260 may temporarily storeinput/output data (e.g., phonebook data, messages, still images, videoand the like). Also, the memory 260 may store data related to variouspatterns of vibrations and audio output upon the touch input on thetouch screen.

In some embodiments, software components including an operating system(not shown), a module performing a wireless communication unit 210function, a module operating together with the user input unit 230, amodule operating together with the A/V input unit 220, a moduleoperating together with the output unit 250 may be stored in the memory260. The operating system (e.g., LINUX, UNIX, OS X, WINDOWS, Chrome,Symbian, iOS, Android, VxWorks, or other embedded operating systems) mayinclude various software components and/or drivers to control systemtasks such as memory management, power management, and the like.

In addition, the memory 260 may store a setup program associated withcontactless power transfer or wireless charging. The setup program maybe implemented by the controller 280.

Furthermore, the memory 260 may store an application associated withcontactless power transfer (or wireless charging) downloaded from anapplication providing server (for example, an app store). The wirelesscharging related application is a program for controlling wirelesscharging transmission, and thus the electronic device 200 may receivepower from the wireless power transmitter 100 in a wireless manner orestablish connection for data communication with the wireless powertransmitter 100 through the relevant program.

The memory 260 may be implemented using any type of suitable storagemedium including a flash memory type, a hard disk type, a multimediacard micro type, a memory card type (e.g., SD or xD memory), a randomaccess memory (RAM), a static random access memory (SRAM), a read-onlymemory (ROM), an electrically erasable programmable read-only memory(EEPROM), a programmable read-only memory (PROM), a magnetic memory, amagnetic disk, an optical disk, and the like. Also, the terminal 200 maybe operated in association with a web storage performing the storagefunction of the memory 160 on the Internet.

The interface unit 270 may generally be implemented to interface theportable terminal with all external devices. The interface unit 270 mayallow a data reception from an external device, a power delivery to eachcomponent in the terminal 200, or a data transmission from the terminal200 to an external device. The interface unit 270 may include, forexample, wired/wireless headset ports, external charger ports,wired/wireless data ports, memory card ports, ports for coupling deviceshaving an identification module, audio input/output (I/O) ports, videoinput/output (I/O) ports, earphone ports, and the like.

The identification module may be configured as a chip for storingvarious information required to authenticate an authority to use theterminal 200, which may include a User Identity Module (UIM), aSubscriber Identity Module (SIM), and the like. Also, the device havingthe identification module (hereinafter, referred to as “identificationdevice”) may be implemented in a type of smart card. Hence, theidentification device can be coupled to the terminal 200 via a port.

Also, the interface unit may serve as a path for power to be suppliedfrom an external cradle to the terminal 200 when the terminal 100 isconnected to the external cradle or as a path for transferring variouscommand signals inputted from the cradle by a user to the terminal 200.Such various command signals or power inputted from the cradle mayoperate as signals for recognizing that the terminal 200 has accuratelybeen mounted to the cradle.

The controller 280 typically controls the overall operations of theterminal 200. For example, the controller 280 performs the control andprocessing associated with telephony calls, data communications, videocalls, and the like. The controller 280 may include a multimedia module281 for multimedia playback. The multimedia module 281 may beimplemented within the controller 280, or implemented separately fromthe controller 280.

The controller 280 can perform a pattern recognition processing so as torecognize a writing input or image drawing input carried out on thetouch screen as a text or image.

The controller 280 performs wired or wireless charging according to theuser input or internal input. Here, the internal input represents asignal for notifying that an induced current generated from a secondarycoil within the terminal has been detected.

When the foregoing wireless charging is carried out, an operation ofallowing the controller 280 to control each constituent element will bedescribed in detail below with reference to the operation phase in FIG.14. As described above, the Power reception control unit (or POWERRECEIVING CONTROL UNIT) 292 within the power supply unit 290 may beimplemented to be included in the controller 280, and in the presentdisclosure, it should be understood that the controller 280 performs theoperation by the Power reception control unit (or POWER RECEIVINGCONTROL UNIT) 292.

The power supply unit 290 receives internal and external power under thecontrol of the controller 280 to supply power required for the operationof each constituent element.

The power supply unit 290 is provided with a battery 299 for supplyingpower to each constituent element of the terminal 200, and the battery299 may include a charger 298 for performing wired or wireless charging.

The present disclosure discloses a mobile terminal as an example of theapparatus for receiving power in a wireless manner, but it would beeasily understood by those skilled in the art that the configurationaccording to the embodiment disclosed herein may be applicable to astationary terminal, such as a digital TV, a desktop computer, and thelike, excluding a case where it is applicable to only the mobileterminal.

FIGS. 11A and 11B—Backscatter Modulation

FIGS. 11A and 11B is a view illustrating the concept of transmitting andreceiving a packet between a wireless power transmitter and anelectronic device through the modulation and demodulation of a wirelesspower signal in transferring power in a wireless manner disclosedherein.

Referring to FIG. 11A, the wireless power signal formed by the powerconversion unit 111 forms a closed-loop within a magnetic field orelectromagnetic field, and therefore, when the electronic device 200modulates the wireless power signal while receiving the wireless powersignal, the wireless power transmitter 100 may detect the modulatedwireless power signal. The power communications modulation/demodulationunit 113 may demodulate the detected wireless power signal, and decodesthe packet from the modulated wireless power signal.

On the other hand, a modulation method used for communication betweenthe wireless power transmitter 100 and the electronic device 200 may beamplitude modulation. As described above, the amplitude modulationmethod may be a backscatter modulation method in which the powercommunications modulation/demodulation unit 293 at the side of theelectronic device 200 changes an amplitude of the wireless power signal10 a formed by the power conversion unit 111 and the Power receptioncontrol unit (or POWER RECEIVING CONTROL UNIT) 292 at the side of thewireless power transmitter 100 detects an amplitude of the modulatedwireless power signal 10 b.

Specifically, further referring to FIG. 11B, the Power reception controlunit (or POWER RECEIVING CONTROL UNIT) 292 at the side of the electronicdevice 200 modulates the wireless power signal 10 a received through thepower receiving unit 291 by changing a load impedance within the powercommunications modulation/demodulation unit 293. The Power receptioncontrol unit (or POWER RECEIVING CONTROL UNIT) 292 modulates thewireless power signal 10 a to include a packet including a power controlmessage to be transmitted to the wireless power transmitter 100.

Then, the power transmission control unit 112 at the side of thewireless power transmitter 100 demodulates the modulated wireless powersignal 10 b through an envelope detection process, and decodes thedetected signal 10 c into digital data 10 d. The demodulation processdetects a current or voltage flowing into the power conversion unit 111to be classified into two states, a HI phase and a LO phase, andacquires a packet to be transmitted by the electronic device 200 basedon digital data classified according to the states.

Hereinafter, a process of allowing the wireless power transmitter 100 toacquire a power control message to be transmitted by the electronicdevice 200 from the demodulated digital data will be described.

FIGS. 12A and 12B—Bit Encoding, Byte Format

FIGS. 12A and 12B is a view illustrating a method of showing data bitsand byte constituting a power control message provided by the wirelesspower transmitter 100.

Referring to FIG. 12A, the power transmission control unit 112 detectsan encoded bit using a clock signal (CLK) from an envelope detectedsignal. The detected encoded bit is encoded according to a bit encodingmethod used in the modulation process at the side of the electronicdevice 200. The bit encoding method may correspond to any one ofnon-return to zero (NRZ) and bi-phase encoding.

For instance, the detected bit may be a differential bi-phase (DBP)encoded bit. According to the DBP encoding, the Power reception controlunit (or POWER RECEIVING CONTROL UNIT) 292 at the side of the electronicdevice 200 is allowed to have two state transitions to encode data bit1, and to have one state transition to encode data bit 0. In otherwords, data bit 1 may be encoded in such a manner that a transitionbetween the HI state and LO state is generated at a rising edge andfalling edge of the clock signal, and data bit 0 may be encoded in sucha manner that a transition between the HI state and LO state isgenerated at a rising edge of the clock signal.

On the other hand, the power transmission control unit 112 may acquiredata in a byte unit using a byte format constituting a packet from a bitstring detected according to the bit encoding method. For instance, thedetected bit string may be transferred by using a 11-bit asynchronousserial format as illustrated in FIG. 12B. In other words, the detectedbit may include a start bit indicating the beginning of a byte and astop bit indicating the end of a byte, and also include data bits (b0 tob7) between the start bit and the stop bit. Furthermore, it may furtherinclude a parity bit for checking an error of data. The data in a byteunit constitutes a packet including a power control message.

FIG. 13—Packet Format

FIG. 13 is a view illustrating a packet including a power controlmessage used in a contactless power transfer method according to theembodiments disclosed herein.

The packet 500 may include a preamble 510, a header 520, a message 530,and a checksum 540.

The preamble 510 may be used to perform synchronization with datareceived by the wireless power transmitter 100 and detect the start bitof the header 520. The preamble 510 may be configured to repeat the samebit. For instance, the preamble 510 may be configured such that data bit1 according to the DBP encoding is repeated eleven to twenty five times.

The header 520 may be used to indicate a type of the packet 500. A sizeof the message 530 and the kind thereof may be determined based on avalue indicated by the header 520. The header 520 is a value having apredetermined size to be positioned subsequent to the preamble 510. Forinstance, the header 520 may be a byte in size.

The message 530 may be configured to include data determined based onthe header 520. The message 530 has a predetermined size according tothe kind thereof.

The checksum 540 may be used to detect an error that can be occurred inthe header 520 and the message 530 while transmitting a power controlmessage. The header 520 and the message 530 excluding the preamble 510for synchronization and the checksum 540 for error checking may bereferred to as command-packet.

FIG. 14—Operation Phases

Hereinafter, description will be given of operation phases of thewireless power transmitter 100 and the electronic device 200.

FIG. 14 illustrates the operation phases of the wireless powertransmitter 100 and electronic device 200 according to the embodimentsdisclosed herein. Furthermore, FIGS. 15 through 20 illustrates thestructure of packets including a power control message between thewireless power transmitter 100 and electronic device 200.

Referring to FIG. 14, the operation phases of the wireless powertransmitter 100 and the electronic device 200 for wireless powertransfer may be divided into a selection phase (state) 610, a ping phase620, an identification and configuration phase 630, and a power transferphase 640.

The wireless power transmitter 100 detects whether or not objects existwithin a range that the wireless power transmitter 100 can transmitpower in a wireless manner in the selection state 610, and the wirelesspower transmitter 100 sends a detection signal to the detected objectand the electronic device 200 sends a response to the detection signalin the ping state 620.

Furthermore, the wireless power transmitter 100 identifies theelectronic device 200 selected through the previous states and acquiresconfiguration information for power transmission in the identificationand configuration state 630. The wireless power transmitter 100transmits power to the electronic device 200 while controlling powertransmitted in response to a control message received from theelectronic device 200 in the power transfer state 640.

Hereinafter, each of the operation phases will be described in detail.

1) Selection State

The wireless power transmitter 100 in the selection state 610 performs adetection process to select the electronic device 200 existing within adetection area. The detection area, as described above, refers to aregion in which an object within the relevant area can affect on thecharacteristic of the power of the power conversion unit 111. Comparedto the ping state 620, the detection process for selecting theelectronic device 200 in the selection state 610 is a process ofdetecting a change of the power amount for forming a wireless powersignal in the power conversion unit at the side of the wireless powertransmitter 100 to check whether any object exists within apredetermined range, instead of the scheme of receiving a response fromthe electronic device 200 using a power control message. The detectionprocess in the selection state 610 may be referred to as an analog pingprocess in the aspect of detecting an object using a wireless powersignal without using a packet in a digital format in the ping state 620which will be described later.

The wireless power transmitter 100 in the selection state 610 can detectthat an object comes in or out within the detection area. Furthermore,the wireless power transmitter 100 can distinguish the electronic device200 capable of transferring power in a wireless manner from otherobjects (for example, a key, a coin, etc.) among objects located withinthe detection area.

As described above, a distance that can transmit power in a wirelessmanner may be different according to the inductive coupling method andresonance coupling method, and thus the detection area for detecting anobject in the selection state 610 may be different from one another.

First, in case where power is transmitted according to the inductivecoupling method, the wireless power transmitter 100 in the selectionstate 610 can monitor an interface surface (not shown) to detect thealignment and removal of objects.

Furthermore, the wireless power transmitter 100 may detect the locationof the electronic device 200 placed on an upper portion of the interfacesurface. As described above, the wireless power transmitter 100 formedto include one or more transmitting coils may perform the process ofentering the ping state 620 in the selection state 610, and checkingwhether or not a response to the detection signal is transmitted fromthe object using each coil in the ping state 620 or subsequentlyentering the identification state 630 to check whether identificationinformation is transmitted from the object. The wireless powertransmitter 100 may determine a coil to be used for contactless powertransfer based on the detected location of the electronic device 200acquired through the foregoing process.

Furthermore, when power is transmitted according to the resonancecoupling method, the wireless power transmitter 100 in the selectionstate 610 can detect an object by detecting that any one of a frequency,a current and a voltage of the power conversion unit is changed due toan object located within the detection area.

On the other hand, the wireless power transmitter 100 in the selectionstate 610 may detect an object by at least any one of the detectionmethods using the inductive coupling method and resonance couplingmethod. The wireless power transmitter 100 may perform an objectdetection process according to each power transmission method, andsubsequently select a method of detecting the object from the couplingmethods for contactless power transfer to advance to other states 620,630, 640.

On the other hand, for the wireless power transmitter 100, a wirelesspower signal formed to detect an object in the selection state 610 and awireless power signal formed to perform digital detection,identification, configuration and power transmission in the subsequentstates 620, 630, 640 may have a different characteristic in thefrequency, strength, and the like. It is because the selection state 610of the wireless power transmitter 100 corresponds to an idle state fordetecting an object, thereby allowing the wireless power transmitter 100to reduce consumption power in the idle state or generate a specializedsignal for effectively detecting an object.

2) Ping State

The wireless power transmitter 100 in the ping state 620 performs aprocess of detecting the electronic device 200 existing within thedetection area through a power control message. Compared to thedetection process of the electronic device 200 using a characteristic ofthe wireless power signal and the like in the selection state 610, thedetection process in the ping state 620 may be referred to as a digitalping process.

The wireless power transmitter 100 in the ping state 620 forms awireless power signal to detect the electronic device 200, modulates thewireless power signal modulated by the electronic device 200, andacquires a power control message in a digital data format correspondingto a response to the detection signal from the modulated wireless powersignal. The wireless power transmitter 100 may receive a power controlmessage corresponding to the response to the detection signal torecognize the electronic device 200 which is a subject of powertransmission.

The detection signal formed to allowing the wireless power transmitter100 in the ping state 620 to perform a digital detection process may bea wireless power signal formed by applying a power signal at a specificoperating point for a predetermined period of time. The operating pointmay denote a frequency, duty cycle, and amplitude of the voltage appliedto the transmitting (Tx) coil. The wireless power transmitter 100 maygenerate the detection signal generated by applying the power signal ata specific operating point for a predetermined period of time, andattempt to receive a power control message from the electronic device200.

On the other hand, the power control message corresponding to a responseto the detection signal may be a message indicating a strength of thewireless power signal received by the electronic device 200. Forexample, the electronic device 200 may transmit a signal strength packet5100 including a message indicating the received strength of thewireless power signal as a response to the detection signal asillustrated in FIG. 15. The packet 5100 may include a header 5120 fornotifying a packet indicating the signal strength and a message 5130indicating a strength of the power signal received by the electronicdevice 200. The strength of the power signal within the message 5130 maybe a value indicating a degree of inductive coupling or resonancecoupling for power transmission between the wireless power transmitter100 and the electronic device 200.

The wireless power transmitter 100 may receive a response message to thedetection signal to find the electronic device 200, and then extend thedigital detection process to enter the identification and configurationstate 630. In other words, the wireless power transmitter 100 maintainsthe power signal at a specific operating point subsequent to finding theelectronic device 200 to receive a power control message required in theidentification and configuration state 630.

However, if the wireless power transmitter 100 is not able to find theelectronic device 200 to which power can be transferred, then theoperation phase of the wireless power transmitter 100 will be returnedto the selection state 610.

3) Identification and Configuration State

The wireless power transmitter 100 in the identification andconfiguration state 630 may receive identification information and/orconfiguration information transmitted by the electronic device 200,thereby controlling power transmission to be effectively carried out.

The electronic device 200 in the identification and configuration state630 may transmit a power control message including its ownidentification information. For this purpose, the electronic device 200,for instance, may transmit an identification packet 5200 including amessage indicating the identification information of the electronicdevice 200 as illustrated in FIG. 16A. The packet 5200 may include aheader 5220 for notifying a packet indicating identification informationand a message 5230 including the identification information of theelectronic device. The message 5230 may include information (2531 and5232) indicating a version of the contract for contactless powertransfer, information 5233 for identifying a manufacturer of theelectronic device 200, information 5234 indicating the presence orabsence of an extended device identifier, and a basic device identifier5235. Furthermore, if it is displayed that an extended device identifierexists in the information 5234 indicating the presence or absence of anextended device identifier, then an extended identification packet 5300including the extended device identifier as illustrated in FIG. 16B willbe transmitted in a separate manner. The packet 5300 may include aheader 5320 for notifying a packet indicating an extended deviceidentifier and a message 5330 including the extended device identifier.When the extended device identifier is used as described above,information based on the manufacturer's identification information 5233,the basic device identifier 5235 and the extended device identifier 5330will be used to identify the electronic device 200.

The electronic device 200 may transmit a power control message includinginformation on expected maximum power in the identification andconfiguration state 630. To this end, the electronic device 200, forinstance, may transmit a configuration packet 5400 as illustrated inFIG. 17. The packet may include a header 5420 for notifying that it is aconfiguration packet and a message 5430 including information on theexpected maximum power. The message 5430 may include power class 5431,information 5432 on expected maximum power, an indicator 5433 indicatinga method of determining a current of a main cell at the side of thewireless power transmitter, and the number 5434 of optionalconfiguration packets. The indicator 5433 may indicate whether or not acurrent of the main cell at the side of the wireless power transmitteris determined as specified in the contract for wireless power transfer.

Meanwhile, the electronic device 200 according to the exemplaryembodiments may transmit a power control message, which includesrequired power information thereof and associated profile information,to the wireless power transmitter 100. In some exemplary embodiments,the required power information related to the electronic device 200 orthe profile information may be transmitted by being included in theconfiguration packet 5400 as illustrated in FIG. 17. Alternatively, therequired power information related to the electronic device 200 or theprofile information may be transmitted by being included in a separatepacket for configuration.

On the other hand, the wireless power transmitter 100 may generate apower transfer contract which is used for power charging with theelectronic device 200 based on the identification information and/orconfiguration information. The power transfer contract may include thelimits of parameters determining a power transfer characteristic in thepower transfer state 640.

The wireless power transmitter 100 may terminate the identification andconfiguration state 630 and return to the selection state 610 prior toentering the power transfer state 640. For instance, the wireless powertransmitter 100 may terminate the identification and configuration state630 to find another electronic device that can receive power in awireless manner.

4) Power Transfer State

The wireless power transmitter 100 in the power transfer state 640transmits power to the electronic device 200.

The wireless power transmitter 100 may receive a power control messagefrom the electronic device 200 while transferring power, and control acharacteristic of the power applied to the transmitting coil in responseto the received power control message. For example, the power controlmessage used to control a characteristic of the power applied to thetransmitting coil may be included in a control error packet 5500 asillustrated in FIG. 18. The packet 5500 may include a header 5520 fornotifying that it is a control error packet and a message 5530 includinga control error value. The wireless power transmitter 100 may controlthe power applied to the transmitting coil according to the controlerror value. In other words, a current applied to the transmitting coilmay be controlled so as to be maintained if the control error value is“0”, reduced if the control error value is a negative value, andincreased if the control error value is a positive value.

The wireless power transmitter 100 may monitor parameters within a powertransfer contract generated based on the identification informationand/or configuration information in the power transfer state 640. As aresult of monitoring the parameters, if power transmission to theelectronic device 200 violates the limits included in the power transfercontract, then the wireless power transmitter 100 may cancel the powertransmission and return to the selection state 610.

The wireless power transmitter 100 may terminate the power transferstate 640 based on a power control message transferred from theelectronic device 200.

For example, if the charging of a battery has been completed whilecharging the battery using power transferred by the electronic device200, then a power control message for requesting the suspension ofwireless power transfer will be transferred to the wireless powertransmitter 100. In this case, the wireless power transmitter 100 mayreceive a message for requesting the suspension of the powertransmission, and then terminate wireless power transfer, and return tothe selection state 610.

For another example, the electronic device 200 may transfer a powercontrol message for requesting renegotiation or reconfiguration toupdate the previously generated power transfer contract. The electronicdevice 200 may transfer a message for requesting the renegotiation ofthe power transfer contract when it is required a larger or smalleramount of power than the currently transmitted power amount. In thiscase, the wireless power transmitter 100 may receive a message forrequesting the renegotiation of the power transfer contract, and thenterminate contactless power transfer, and return to the identificationand configuration state 630.

To this end, a message transmitted by the electronic device 200, forinstance, may be an end power transfer packet 5600 as illustrated inFIG. 19. The packet 5600 may include a header 5620 for notifying that itis an end power transfer packet and a message 5630 including an endpower transfer code indicating the cause of the suspension. The endpower transfer code may indicate any one of charge complete, internalfault, over temperature, over voltage, over current, battery failure,reconfigure, no response, and unknown error.

Wireless Power Transfer in Many-to-One Communication

Hereinafter, a wireless power transfer in a many-to-one communicationwill be described.

Especially, the technology disclosed herein is a wireless (contactless)power transfer method associated with a wireless power control method,namely, a method for controlling power transferred from a wireless powertransmitter for optimal power transfer when a plurality of wirelesspower receivers are present.

First, the many-to-one communication may indicate a method in which onewireless power transmitter (Tx) communicates with a plurality ofwireless power receivers (Rx).

The many-to-one communication may be implemented by a unidirectionalcommunication method and a bidirectional communication method.

The unidirectional communication may be a method in which only awireless power receiver transmits a required message to a wireless powertransmitter. To this end, the wireless power receiver may modulate awireless power signal, which has been formed by the wireless powertransmitter, to transmit a required message (or packet) to the wirelesspower transmitter.

The bidirectional communication may be a method in which both thewireless power transmitter and the wireless power receiver are able toexchange required messages with each other. Here, each of the wirelesspower transmitter and the wireless power receiver may include amodulation/demodulation unit, and may modulate the wireless power signalthrough the modulation/demodulation unit such that the required messagecan be included in a wireless power signal.

In view of a wireless power transfer, the power control method mayindicate a method for controlling a quantity (amount) of powertransmitted by the wireless power transmitter based on a control error.

The control error may be generated based on various references. Forexample, the control error may indicate a value obtained by subtractinga quantity of power, which a wireless power receiver is actuallyreceiving from a wireless power transmitter, from a quantity of powerdesired by the wireless power receiver. In addition, it may be obviousto a person skilled in the art that the control error can be generatedbased on various references.

FIG. 20A illustrates the wireless power transfer method (or wirelesspower controlling method) based on the control error in a one-to-onecommunication.

Referring to FIG. 20A, one wireless power transmitter Tx is transmittinga wireless power signal, which has a resonant frequency of f0, to onewireless power receiver Rx.

In this case, the wireless power receiver Rx may detect (or generate),as a control error, a value obtained by subtracting a quantity of power,which it is actually receiving, from a target quantity of power (or aquantity of power that the wireless power receiver desires to receive).

The wireless power receiver Rx may transmit the control error to thewireless power transmitter Tx.

The wireless power transmitter Tx may control the quantity of wirelesspower, which is transferred to the wireless power receiver, based on thecontrol error.

For example, the wireless power transmitter Tx may control the quantityof wireless power such that the control error can be lower than aspecific value (for example, 1). Also, the wireless power transmitter Txmay control the quantity of wireless power such that the control errorcan be converged into ‘0’ (or a value close to ‘0’).

The control of the quantity of wireless power may be implemented byadjusting (or setting) a transmission parameter of the wireless powersignal formed by the wireless power transmitter Tx.

For example, the transmission parameter may be a frequency (or resonantfrequency) of the wireless power signal. The wireless power transmitterTx may adjust the quantity of wireless power transferred by adjustingthe frequency of the wireless power signal.

FIG. 20B is an exemplary view illustrating a wireless power controllingmethod in a many-to-one communication.

Referring to FIG. 20B, one wireless power transmitter Tx may transferpower in a wireless manner to a plurality of wireless power receiversRx1 to Rx3 by generating (forming) a wireless power signal having aresonant frequency of f0.

As illustrated in FIG. 20A, the plurality of wireless power receiversRx1 to Rx3 may receive power in a wireless manner by receiving thewireless power signal from the wireless power transmitter Tx, and detecta control error to transmit to the wireless power transmitter Tx.

Here, the wireless power transmitter Tx should control the respectivequantities of wireless power with respect to the plurality of wirelesspower receivers Rx1 to Rx3 based on control errors (totally threecontrol error information) acquired from the plurality of wireless powerreceivers Rx1 to Rx3, respectively.

Here, if the quantity of wireless power is controlled based on a controlerror acquired from only one wireless power receiver (for example, Rx1),the control error for the Rx1 may be adjustable, but the control errorsfor the other wireless power receivers Rx2 and Rx3 may not appropriatelybe adjusted.

Hereinafter, a wireless power transfer method (or a wireless powercontrolling method) in a many-to-one communication will be describedwith reference to FIGS. 21 to 29.

Description of Wireless Power Transmitter According to ExemplaryEmbodiments

The wireless power transmitter according to exemplary embodimentsdisclosed herein may include a power transmission unit to transmit awireless power signal and acquire control errors from a plurality ofwireless power receivers, which receive the wireless power signal, and acontroller to detect a transmission parameter corresponding to each ofthe plurality of wireless power receivers based on the acquired controlerrors and control the power transfer unit to transfer power in awireless manner to the plurality of wireless power receivers by formingthe wireless power signal based on the detected transmission parameters.

FIG. 21 is a block diagram illustrating the configuration of a wirelesspower transmitter in accordance with exemplary embodiments.

Also, FIG. 21 is a block diagram illustrating a wireless powertransmitter further including constituent elements in addition to theconfiguration illustrated in FIG. 2A.

Referring to FIG. 21, the wireless power transmitter 100 may include apower transmission unit (or wireless power transmission unit) 110 and acontroller 180, both supporting at least one of the inductive couplingmethod and the resonance coupling method.

In addition to them, in order to control a quantity of wireless powertransferred, the wireless power transmitter 100 may further include apower supply unit 190, a sensing unit 120, a communication unit 130, anoutput unit 140, and a memory 150.

In addition to those elements, the wireless power transmitter 100 mayfurther include various constituent elements for performing a functionof controlling the quantity of wireless power.

Hereinafter, each constituent element will be described.

The power transmission unit 110 may transmit a wireless power signal,and acquire a control error from a wireless power receiver 200 which hasreceived the wireless power signal.

The wireless power receiver 200 may include plurality of receivers (or aplurality of wireless power receivers).

The power transmission unit 110 may acquire the control error in variousmanners.

For example, the power transmission unit 110 may sequentially acquirecontrol errors, which correspond to the plurality of wireless powerreceivers 200, respectively, from the plurality of wireless powerreceivers 200.

Here, the plurality of wireless power receivers 200 may transmit thecontrol errors to the wireless power transmitter 100 via time slotsrespectively allocated thereto.

Here, the time slot may be formed by dividing a time section fortransmission of the wireless power signal by a time axis so as to beallocated to the plurality of wireless power receivers, respectively.

In accordance with one exemplary embodiment, the control errorcorresponding to each of the plurality of wireless power receivers 200may be generated based on at least one of a value obtained bysubtracting an actually received amount of power from a target amount ofpower corresponding to each of the plurality of wireless power receivers200, a value obtained by subtracting an actually received receiving sidevoltage from a target receiving side voltage corresponding to each ofthe plurality of wireless power receivers 200, a value obtained bysubtracting an actually received receiving side current from a targetreceiving side current corresponding to each of the plurality ofwireless power receivers 200, a value obtained by subtractingtransmission efficiency upon actually receiving wireless power from atarget transmission efficiency corresponding to each of the plurality ofwireless power receivers 200, and a value obtained by subtracting atransmission gain upon actually receiving wireless power from a targettransmission gain corresponding to each of the plurality of wirelesspower receivers 200.

Here, the transmission efficiency may be a ratio between transmissionpower of the wireless power transmitter and reception powercorresponding to each of the plurality of wireless power receivers.

Also, the transmission gain may be a ratio between a transmitting sidevoltage corresponding to the wireless power transmitter and a receivingside voltage corresponding to each of the plurality of wireless powerreceivers 200.

In addition, the reception power may be detected based on a receivingside voltage and a receiving side current corresponding to each of theplurality of wireless power receivers 200.

In accordance with one exemplary embodiment, the plurality of wirelesspower receivers 200 may transmit a packet, which includes a powercontrol message, to the wireless power transmitter.

Here, the control error may be transmitted to the wireless powertransmitter by being included in the packet, which includes the powercontrol message.

The packet including the power control message may be generated as thewireless power signal is modulated by the plurality of wireless powerreceivers 200.

The controller 180 may perform various functions for performing acontrol function for wireless power, which is transmitted by adjusting atransmission parameter of the wireless power signal.

For example, in order to perform the wireless power control function,the controller 180 may control the power transmission unit 110, thesensing unit 120, the communication unit 130, the output unit 140, thememory 150 and the power supply unit 190.

The controller 180 may be implemented with various forms. For example,the controller 180 may be implemented a separate module from the powertransmission control unit 112 within the power transmission unit 110,which has been described with reference to FIG. 2, or a single module.

In exemplary embodiments, the controller 180 may detect transmissionparameters corresponding to the plurality of wireless power receivers200, respectively, based on the acquired control errors.

The transmission parameter may be a parameter associated with thewireless power signal formed by the wireless power transmitter 100.

For example, the transmission parameter may be at least one of afrequency, an amplitude and a phase of the wireless power signal, or atime interval for transmission of the wireless power signal.

Also, the controller 180 may control the power transmission unit 110 totransfer power in a wireless manner to the plurality of wireless powerreceivers 200 by forming the wireless power signal based on the detectedtransmission powers.

In one exemplary embodiment, the transmission parameter may be atransmission frequency corresponding to each of the plurality ofwireless power receivers.

Here, the controller 180 may periodically change the frequency of thewireless power signal into a transmission frequency corresponding toeach of the plurality of wireless power receivers.

Also, the controller 180 may transfer power in a wireless manner to theplurality of wireless power receivers 200 by forming the wireless powersignal using the periodically changed transmission frequency.

In one exemplary embodiment, the controller 180 may detect an optimaltransmission parameter corresponding to the plurality of wireless powerreceivers 200 based on the detected transmission parameters.

Here, the controller 180 may transfer power in a wireless manner to theplurality of wireless power receivers 200 by forming the wireless powersignal based on the optimal transmission parameter.

In one exemplary embodiment, the optimal transmission parameter may begenerated by processing the detected transmission parameters in astatistical manner.

Here, the statistical manner may be a method based on at least one ofaverage, variance and standard deviation of the transmission parameters.

In one exemplary embodiment, the transmission parameters may betransmission frequencies corresponding to the plurality of wirelesspower receivers, respectively.

In this case, the controller 180 may set a weight for each of theplurality of wireless power receivers 200 based on the control errors orthe transmission parameters.

The controller 180 may set a transmission time interval for each of theplurality of transmission power receivers 200 based on the weights.

The controller 180 may thus transfer power in a wireless manner byforming the wireless power signal having the transmission frequenciescorresponding to the plurality of wireless power receivers 200,respectively, for the respectively set transmission time intervals.

Here, the weight may be proportional to the control error correspondingto each of the plurality of wireless power receivers 200.

For example, if it is assumed that the control error of a first wirelesspower receiver is 10 and the control error of a second wireless powerreceiver is 30, the wireless power transmitter 100 (or the controller180) may set the weight of the first wireless power receiver to 1 andthe weight of the second wireless power receiver to 2.

Here, the wireless power transmitter 100 may perform a setting operationin such a manner that a time for forming the wireless power signalhaving the transmission frequency corresponding to the second wirelesspower receiver is three times longer than a time for forming thewireless power signal having the transmission frequency corresponding tothe second wireless power receiver.

The controller 180 may decide the transmission parameter such that thecontrol error of each of the plurality of wireless power receivers 200can be less than a reference value.

Also, the controller 180 may decide the transmission parameter such thata control error value of a specific wireless power receiver of theplurality of wireless power receivers does not increase more than aspecific value.

The transmission parameter may be decided based on at least one ofwhether or not a damage is caused on the plurality of wireless powerreceivers (or at least one of the plurality of wireless power receivers)or whether or not the plurality of wireless power receivers (or at leastone of the plurality of wireless power receivers) are able to wirelesslyreceive power from the wireless power transmitter.

This is because the wireless power transmitter 100 should satisfy acondition in which the plurality of wireless power receivers 200 canstably receive power in a wireless manner while performing the wirelesspower control function.

In one exemplary embodiment, the wireless power transmitter 100 (or thecontroller 180) may request for transmission of the control error fromeach of the plurality of wireless power receivers 200.

The control error transmission request may be performed at an initialstep of performing the wireless power control function or in response toa new environmental change during wireless power transfer.

For example, the control error transmission request may be performedwhen the control error is more than a reference value, when a newwireless power receiver is placed in a specific area, when the number ofwireless power receivers existing in the specific area changes, when aposition of at least one wireless power receiver existing in thespecific area changes, and when there is a periodically received requestor a request received from the wireless power receiver.

Here, the specific area may be an area through which the wireless powersignal passes or an area on which the wireless power receiver can besensed.

FIG. 22 is an exemplary view illustrating a method in which a wirelesspower transmitter requests for a control error and acquires the controlerror.

Referring to FIG. 22, the wireless power transmitter 100 may transmit acontrol error request (control error req.) for acquiring a control errorto each of the plurality of wireless power receivers 200. This may bereferred to as a power control mode of the wireless power transmitter100.

Here, each of the plurality of wireless power receivers 200 may transmitits own control error to the wireless power transmitter via eachallocated time slot.

The time slot may be formed by dividing a time section for transmissionof the wireless power signal by a time axis so as to be allocated to theplurality of wireless power receivers, respectively.

For example, a first wireless power receiver may be allocated with atime-slot₁, and transmit its control error to the wireless powertransmitter for a time interval of the time-slot₁.

Also, for example, a second wireless power receiver may be allocatedwith a time-slot2, and transmit its control error to the wireless powertransmitter for a time interval of the time-slot₂.

Similarly, a max^(th) wireless power receiver may be allocated with atime-slot_(max), and transmit its control error to the wireless powertransmitter for a time interval of the time-slot_(max).

Here, the wireless power transmitter 100 may adjust power using only thecontrol error transmitted only on the first time slot (time-slot₁),thereby finding a resonant frequency for optimizing power transmissionefficiency with respect to a specific receiver (or the first wirelesspower receiver).

Here, the Wireless power transmitter (or WIRELESS POWER TRANSFERAPPARATUS) may check whether divergence of control error occurs (or hasoccurred) on one or more receiver rather than the specific receiver (ormay check whether control error value of on one or more receiver ratherthan the specific receiver does not increase more than a specificvaluemore than a specific value).

Next, the wireless power transmitter 100 may adjust power using only thecontrol error transmitted only on the second time slot (time-slot₂),thereby finding a resonant frequency for optimizing power transmissionefficiency with respect to another receiver (or the second wirelesspower receiver).

Also, here, the Wireless power transmitter (or WIRELESS POWER TRANSFERAPPARATUS) may check whether divergence of control error occurs (or hasoccurred) on one or more receiver rather than the another receiver (ormay check whether control error value of on one or more receiver ratherthan the another receiver does not increase more than a specificvaluemore than a specific value).

The wireless power transmitter 100 may repeat the processes as manytimes as the number of receivers (or the plurality of wireless powerreceivers).

Afterwards, the wireless power transmitter 100 may calculate an averageof optimal resonant frequencies for respective receivers (or theplurality of wireless power receivers), and change a resonant frequencyof the wireless power signal for transferring power to each receiver tothe average frequency.

Accordingly, power may be uniformly supplied to every receiver, and thismay optimize transmission efficiency in many-to-one communication.

In one exemplary embodiment, the plurality of wireless power receivers200 may include a first wireless power receiver and a second wirelesspower receiver.

Here, the controller 180 may acquire a first control error via a timeslot corresponding to the first wireless power receiver, so as to detecta first transmission parameter corresponding to the first wireless powerreceiver.

Also, the controller 180 may acquire a second control error via a timeslot corresponding to the second wireless power receiver, so as todetect a second transmission parameter corresponding to the secondwireless power receiver.

The controller 180 may thus transfer power in a wireless manner to thefirst and second wireless power receivers by forming the wireless powersignal based on the first and second transmission parameters.

In one exemplary embodiment, the power transmission unit 110 maysequentially acquire a control error corresponding to each of theplurality of wireless power receivers from the plurality of wirelesspower receivers.

Here, the controller 180 may detect a transmission parametercorresponding to each of the plurality of wireless power receivers 200,based on the sequentially acquired control errors.

The controller 180 may detect an optimal transmission parametercorresponding to the plurality of wireless power receivers based on thedetected transmission parameters.

Also, the controller 180 may control the power transmission unit 110 totransfer power in a wireless manner to the plurality of wireless powerreceivers 200 by forming the wireless power signal based on the optimaltransmission parameter.

Here, the optimal transmission parameter may be decided as an averagevalue of the transmission parameters corresponding to the plurality ofwireless power receivers 200, respectively.

Also, in one exemplary embodiment, the control error may be generatedbased on a value obtained by subtracting an actually received receivingside voltage from a target receiving side voltage corresponding to eachthe plurality of wireless power receivers 200.

Here, each of the plurality of wireless power receivers 200 may transmita packet including information related to the control error to thewireless power transmitter.

The packet may be generated by modulating the wireless power signal bythe plurality of wireless power receivers.

The sensing unit 120 may be configured to include a sensor for sensing aposition of the wireless power receiver 200. The position informationsensed by the sensing unit 120 may be used by the power conversion unit111 to efficiently transfer power.

For example, in the wireless power transfer which supports the inductivecoupling method, the sensing unit 120 may operate as a positiondetection unit. The position information detected by the sensing unit120 may be used to move or rotate the transmitting coil 1111 a withinthe power conversion unit 111.

For example, the wireless power transmitter 100, which includes theaforementioned one or more transmitting coils, may decide coils of theone or more transmitting coils, which may be placed in an inductivecoupling relation or a resonance coupling relation with receiving coilsof the plurality of wireless power receivers 200, based on the positioninformation related to the wireless power receivers 200.

Meanwhile, the sensing unit 120 may monitor whether or not the wirelesspower receiver 200 accesses a chargeable area. The access or non-accesssensing function of the sensing unit 120 may be performed separate fromor in combination with a function that the power transmission controlunit 112 within the power transmission unit 110 detects access ornon-access of the wireless power receiver 200.

The communication unit 130 may perform wired or wireless datacommunications with the wireless power receiver 200. The communicationunit 130 may include an electronic component for at least any one ofBluetooth™, Zigbee, Ultra Wide Band (UWB), Wireless USB, Near FieldCommunication (NFC), and Wireless LAN.

The output unit 140 may include at least one of a display unit 141 andan audio output unit (or SOUND OUTPUT UNIT) 142. The display unit 141may include at least one of a liquid crystal display (LCD), a thin filmtransistor-liquid crystal display (TFT-LCD), an organic light-emittingdiode (OLED), a flexible display, and a three-dimensional (3D) display.The display unit 141 may display a charging state under the control ofthe control unit (or Controller) 180.

The memory 150 may include at least one storage medium of a flash memorytype, a hard disk type, a multimedia card micro type, a card type memory(e.g., SD or XD memory), a random access memory (RAM), a static randomaccess memory (SRAM), a read-only memory (ROM), an electrically erasableprogrammable read-only memory (EEPROM), a programmable read-only memory(PROM), a magnetic memory, a magnetic disk, an optical disk, and thelike. The wireless power transmitter 100 may operate in association witha web storage performing the storage function of the memory 150 on theInternet. A program or commands performing the foregoing functions ofthe wireless power transmitter 100 may be stored in the memory 150. Thecontrol unit (or Controller) 180 may perform the program or commandsstored in the memory 150 to transmit power in a wireless manner. Amemory controller (not shown) may be used to allow other constituentelements (e.g., control unit (or Controller) 180) included in thewireless power transmitter 100 to access the memory 150.

In the meantime, the wireless power transmitter 100 for setting afrequency in accordance with exemplary embodiments may be implemented inthe form of a wireless power transmitter illustrated in FIG. 2A.

Wireless Power Transfer Method According to Exemplary Embodiments

A wireless power transfer method for a wireless power transmitter, whichtransfers power in a wireless manner by forming a wireless power signal,in accordance with exemplary embodiments, may include acquiring controlerrors corresponding to a plurality of wireless power receivers,respectively, detecting transmission parameters corresponding to theplurality of wireless power receivers, respectively, based on theacquired control errors, and transferring power in a wireless manner tothe plurality of wireless power receivers by forming the wireless powersignal based on the detected transmission parameters.

FIG. 23 is a flowchart illustrating a wireless power transfer method inaccordance with exemplary embodiments.

Referring to FIG. 23, the wireless power transfer method (or wirelesspower control method) in accordance with the exemplary embodiments mayinclude the following steps.

First, a wireless power transmitter may acquire control errorscorresponding to a plurality of wireless power receivers, respectively(S110)

The wireless power transmitter may detect transmission parameterscorresponding to the plurality of wireless power receivers,respectively, based on the acquired control errors (S120).

Next, the wireless power transmitter may transfer power in a wirelessmanner to the plurality of wireless power receivers by forming thewireless power signal based on the detected transmission parameters(S130).

First Exemplary Embodiment Transmission of Wireless Power Signal withPeriodically Changed Frequency

The first exemplary embodiment may be implemented by part of or incombination of the configurations or steps included in theaforementioned exemplary embodiments, or in combination of theaforementioned exemplary embodiments. To describe the first exemplaryembodiment disclosed in this specification, repetitive description willbe omitted.

A wireless power transfer method for a wireless power transmitter, whichtransfers power in a wireless manner by forming a wireless power signal,in accordance with a first exemplary embodiment, may include acquiringcontrol errors corresponding to a plurality of wireless power receivers,respectively, detecting transmission parameters corresponding to theplurality of wireless power receivers, respectively, based on theacquired control errors, and transferring power in a wireless manner tothe plurality of wireless power receivers by forming the wireless powersignal based on the detected transmission parameters.

Also, in accordance with the first exemplary embodiment, thetransmission parameter is a transmission frequency corresponding to eachof the plurality of wireless power receivers. The transferring of thepower in the wireless manner based on the detected transmissionparameters may include periodically changing the frequency of thewireless power signal to a transmission frequency corresponding to eachof the plurality of wireless power receivers, and transferring power inthe wireless manner by forming the wireless power signal using theperiodically changed transmission frequency.

FIG. 24 is a flowchart illustrating a wireless power transfer method (orwireless power control method) in accordance with a first exemplaryembodiment.

Referring to FIG. 24, a wireless power transfer method in accordancewith a first exemplary embodiment may include the following steps.

First, a wireless power transmitter may acquire control errorscorresponding to a plurality of wireless power receivers, respectively(S110)

The wireless power transmitter may detect transmission parameterscorresponding to the plurality of wireless power receivers,respectively, based on the acquired control errors (S120).

Next, the wireless power transmitter may periodically change thefrequency of the wireless power signal into a transmission frequencycorresponding to each of the plurality of wireless power receivers(S210).

The wireless power transmitter may transfer power in the wireless mannerto the plurality of wireless power receivers by forming the wirelesspower signal using the periodically changed frequency (S220).

FIG. 25 is an exemplary view illustrating the wireless power transfermethod (or wireless power control method) in accordance with the firstexemplary embodiment.

Referring to FIG. 25, for wirelessly supplying power to the plurality ofwireless power receiver 200, the wireless power transmitter 100 mayrequest information related to the control error from each of theplurality of wireless power receivers 200.

Each of the plurality of wireless power receivers 200 may transmit thecontrol error thereof to the wireless power transmitter 100 through eachallocated time slot.

The wireless power transmitter 100 may decide a transmission parameterfor each of the plurality of wireless power receivers 200 based oninformation related to the control error for each of the plurality ofwireless power receivers 200.

In accordance with the first exemplary embodiment, the transmissionparameter may be the frequency of the wireless power signal (or resonantfrequency).

For example, the wireless power transmitter 100 may decide atransmission frequency f0, on which the control error for the firstwireless power receiver of the plurality of wireless power receivers 200is less than a specific value (for example, 1).

The wireless power transmitter 100 may decide a transmission frequencyf1, on which the control error for the second wireless power receiver ofthe plurality of wireless power receivers 200 is less than a specificvalue (for example, 1).

The wireless power transmitter 100 may also decide a transmissionfrequency f2, on which the control error for the third wireless powerreceiver of the plurality of wireless power receivers 200 is less than aspecific value (for example, 1).

Here, the wireless power transmitter 100 may decide a transmission timepoint and a transmission time interval for the wireless power signalwith respect to the first wireless power receiver, the second wirelesspower receiver, and the third wireless power receiver.

Also, the wireless power transmitter 100 may supply power in a wirelessmanner to the first wireless power receiver by forming a wireless powersignal, which has the transmission frequency f0 for the first wirelesspower receiver, at a specific transmission time point and time interval.

The wireless power transmitter 100 may also supply power in a wirelessmanner to the second wireless power receiver by forming a wireless powersignal, which has the transmission frequency f1 for the second wirelesspower receiver, at another specific transmission time point and timeinterval.

In addition, the wireless power transmitter 100 may supply power in awireless manner to the third wireless power receiver by forming awireless power signal, which has the transmission frequency f2 for thethird wireless power receiver, at another specific transmission timepoint and time interval.

Accordingly, the wireless power transmitter 100 may acquire uniformtransmission efficiency with respect to the plurality of wireless powerreceivers by forming the wireless power signal, which is optimized forthe first, second, and third wireless power receivers, respectively.

Second Exemplary Embodiment Formation of Wireless Power Signal ThroughStatistical Manner

The second exemplary embodiment may be implemented by part of or incombination of the configurations or steps included in theaforementioned exemplary embodiments, or in combination of theaforementioned exemplary embodiments. To describe the second exemplaryembodiment disclosed in this specification, repetitive description willbe omitted.

A wireless power transfer method for a wireless power transmitter, whichtransfers power in a wireless manner by forming a wireless power signal,in accordance with a second exemplary embodiment, may include acquiringcontrol errors corresponding to a plurality of wireless power receivers,respectively, detecting transmission parameters corresponding to theplurality of wireless power receivers, respectively, based on theacquired control errors, and transferring power in a wireless manner tothe plurality of wireless power receivers by forming the wireless powersignal based on the detected transmission parameters.

In accordance with the second exemplary embodiment, the transferring ofthe power in the wireless manner based on the detected transmissionparameters may include detecting an optimal transmission parametercorresponding to the plurality of wireless power receivers based on thedetected transmission parameters, and transferring power in the wirelessmanner to the plurality of wireless power receivers by forming thewireless power signal based on the optimal transmission parameter.

In accordance with the second exemplary embodiment, the optimaltransmission parameter may be generated by processing the detectedtransmission parameters in a statistical manner.

Here, the statistical manner may be a method based on at least one of anaverage, variance and standard deviation of the transmission parameters.

FIG. 26 is a flowchart illustrating a wireless power transfer method inaccordance with a second exemplary embodiment.

Referring to FIG. 26, the wireless power transfer method in accordancewith the second exemplary embodiment may include the following steps.

First, a wireless power transmitter may acquire control errorscorresponding to a plurality of wireless power receivers, respectively(S110)

The wireless power transmitter may detect transmission parameterscorresponding to the plurality of wireless power receivers,respectively, based on the acquired control errors (S120).

Next, the wireless power transmitter may detect an average value of thetransmission parameters corresponding to the plurality of wireless powerreceivers as an optimal transmission parameter (S310).

The wireless power transmitter may transfer power in a wireless mannerto the plurality of wireless power receivers by forming the wirelesspower signal based on the optimal transmission parameter (S320).

FIG. 27 is an exemplary view illustrating the wireless power transfermethod in accordance with the second exemplary embodiment.

Referring to FIG. 27, the wireless power transmitter 100 may transmit acontrol error request (control error req.) for acquiring a control errorto each of the plurality of wireless power receivers 200. This may bereferred to as a power control mode of the wireless power transmitter100.

Here, each of the plurality of wireless power receivers 200 may transmitits own control error to the wireless power transmitter via eachallocated time slot.

The time slot may be formed by dividing a time section for transmissionof the wireless power signal by a time axis so as to be allocated to theplurality of wireless power receivers, respectively.

For example, a first wireless power receiver may be allocated with atime-slot1, and transmit its control error to the wireless powertransmitter for a time interval of the time-slot₁.

Also, for example, a second wireless power receiver may be allocatedwith a time-slot2, and transmit its control error to the wireless powertransmitter for a time interval of the time-slot₂.

Similarly, a max^(th) wireless power receiver may be allocated with atime-slot_(max), and transmit its control error to the wireless powertransmitter for a time interval of the time-slot_(max).

Here, the wireless power transmitter 100 may adjust power using only thecontrol error transmitted only on the first time slot (time-slot₁),thereby finding a resonant frequency f0 for optimizing powertransmission efficiency with respect to a specific receiver (or thefirst wireless power receiver).

Next, the wireless power transmitter 100 may adjust power using only thecontrol error transmitted only on the second time slot (time-slot₂),thereby finding a resonant frequency f1 for optimizing powertransmission efficiency with respect to another receiver (or the secondwireless power receiver).

The wireless power transmitter 100 may repeat the processes as manytimes as the number of receivers (or the plurality of wireless powerreceivers).

For example, when the number of wireless power receivers is max, theaforementioned processes may be repeatedly performed up to the max^(th)receiver.

Afterwards, the wireless power transmitter 100 may calculate an averageof optimal resonant frequencies for respective receivers (or theplurality of wireless power receivers), and change a resonant frequency(fnew) capable of transmitting a wireless power signal to each receiverto the average frequency (favg).

Accordingly, power may be uniformly supplied to every receiver, and thismay optimize transmission efficiency in many-to-one communication.

Third Exemplary Embodiment Wireless Power Control Through TimeAllocation

The third exemplary embodiment may be implemented by part of or incombination of the configurations or steps included in theaforementioned exemplary embodiments, or in combination of theaforementioned exemplary embodiments. To describe the third exemplaryembodiment disclosed in this specification, repetitive description willbe omitted.

A wireless power transfer method for a wireless power transmitter, whichtransmits wireless power by forming a wireless power signal, inaccordance with a third exemplary embodiment, may include acquiringcontrol errors corresponding to a plurality of wireless power receivers,respectively, detecting transmission parameters corresponding to theplurality of wireless power receivers, respectively, based on theacquired control errors, and transferring power in a wireless manner tothe plurality of wireless power receivers by forming the wireless powersignal based on the detected transmission parameters.

Also, in accordance with the third exemplary embodiment, thetransmission parameter is a transmission frequency corresponding to eachof the plurality of wireless power receivers. The transferring of thepower in the wireless manner based on the detected transmissionparameters may include setting a weight for each of the plurality ofwireless power receivers based on the detected transmission parameters,setting a transmission time interval for each of the plurality ofwireless power receivers based on the weights, and transferring power inthe wireless manner by forming the wireless power signal having thetransmission frequency corresponding to each of the plurality ofwireless power transmitters for the set transmission time intervals.

In accordance with the third exemplary embodiment, the weight may beproportional to the control error corresponding to each of the pluralityof wireless power receivers.

The transmission parameter may be decided as a value that a controlerror value of a specific wireless power receiver of the plurality ofwireless power receivers does not increase more than a specific value.

The transmission parameter may be decided based on at least one ofwhether or not a damage is caused on the plurality of wireless powerreceivers (or at least one of the plurality of wireless power receivers)or whether or not the plurality of wireless power receivers (or at leastone of the plurality of wireless power receivers) are able to receivepower in a wireless manner from the wireless power transmitter.

FIG. 28 is a flowchart illustrating a wireless power transfer method inaccordance with a third exemplary embodiment.

Referring to FIG. 28, the wireless power transfer method in accordancewith the third exemplary embodiment may include the following steps.

First, a wireless power transmitter may acquire control errorscorresponding to a plurality of wireless power receivers, respectively(S110)

The wireless power transmitter may detect transmission parameterscorresponding to the plurality of wireless power receivers,respectively, based on the acquired control errors (S120).

Next, the wireless power transmitter may transfer power in a wirelessmanner by forming a wireless power signal having a transmissionfrequency corresponding to each of the plurality of wireless powerreceivers for the set transmission time interval (S420).

FIG. 29 is an exemplary view illustrating the wireless power transfermethod in accordance with the third exemplary embodiment.

Referring to FIG. 29, for wirelessly supplying power to the plurality ofwireless power receivers 200, the wireless power transmitter 100 mayrequest information related to a control error from each of theplurality of wireless power receivers 200.

Each of the plurality of wireless power receivers 200 may transmit thecontrol error thereof to the wireless power transmitter 100 through atime slot allocated thereto.

The wireless power transmitter 100 may decide a transmission parameterfor each of the plurality of wireless power receivers 200 based oninformation related to the control error for each of the plurality ofwireless power receivers 200.

In accordance with the first exemplary embodiment, the transmissionparameter may be the frequency of the wireless power signal and atransmission time interval thereof.

For example, the wireless power transmitter 100 may decide atransmission frequency f0, on which a control error for the firstwireless power receiver of the plurality of wireless power receivers 200is less than a specific value (for example, 1), and a transmission timeinterval T1.

The wireless power transmitter 100 may decide a transmission frequencyf1, on which a control error for the second wireless power receiver ofthe plurality of wireless power receivers 200 is less than a specificvalue (for example, 1), and a transmission time interval T2.

The wireless power transmitter 100 may also decide a transmissionfrequency f2, on which a control error for the third wireless powerreceiver of the plurality of wireless power receivers 200 is less than aspecific value (for example, 1), and a transmission time interval T3.

Here, the wireless power transmitter 100 may decide a transmission timepoint for the wireless power signal with respect to the first wirelesspower receiver, the second wireless power receiver, and the thirdwireless power receiver.

Also, the wireless power transmitter 100 may supply power in thewireless manner to the first wireless power receiver by forming thewireless power signal, which has the transmission frequency f0 for thefirst wireless power receiver, at a specific transmission time point forthe transmission time interval T1.

The wireless power transmitter 100 may also supply power in the wirelessmanner to the second wireless power receiver by forming the wirelesspower signal, which has the transmission frequency f1 for the secondwireless power receiver, at another specific transmission time point forthe transmission time interval T2.

In addition, the wireless power transmitter 100 may supply power in thewireless manner to the third wireless power receiver by forming thewireless power signal, which has the transmission frequency f2 for thethird wireless power receiver, at another specific transmission timepoint for the transmission time interval T3.

Accordingly, the wireless power transmitter 100 may acquire uniformtransmission efficiency with respect to the plurality of wireless powerreceivers by forming the wireless power signal, which is optimized forthe first, second, and third wireless power receivers, respectively.

The foregoing method may be implemented in a recording medium readableby a computer or its similar devices by employing, for example,software, hardware or some combinations thereof.

For a hardware implementation, the embodiments described herein may beimplemented by using at least any one of application specific integratedcircuits (ASICs), digital signal processors (DSPs), digital signalprocessing devices (DSPDs), programmable logic devices (PLDs), fieldprogrammable gate arrays (FPGAs), processors, controllers,micro-controllers, microprocessors, other electronic units designed toperform the functions described herein. For example, the foregoingmethods may be implemented by the control unit (or Controller) 180 orpower transmission control unit 112 in the wireless power transmitter100, or implemented by the controller 280 or Power reception controlunit (or POWER RECEIVING CONTROL UNIT) 292 in the electronic device 200.

For a software implementation, the embodiments such as procedures andfunctions disclosed herein may be implemented with separate softwaremodules. Each of the software modules may perform one or more of thefunctions and operations described herein. Software codes may beimplemented by using a software application written in a suitableprogramming language. The software codes may be stored in the memory 150in the wireless power transmitter 100, and implemented by the controlunit (or Controller) 180 or the power transmission control unit 112, andsimilarly, stored in the memory 260 in the electronic device 200, andimplemented by the controller 280 or the Power reception control unit(or POWER RECEIVING CONTROL UNIT) 292.

The scope of the invention will not be limited to the embodimentsdisclosed herein, and thus various modifications, variations, andimprovements can be made in the present invention without departing fromthe spirit of the invention, and within the scope of the appendedclaims.

What is claimed is:
 1. A wireless power transfer method for a wirelesspower transmitter which transfers power in a wireless manner by forminga wireless power signal, the method comprising: detecting a plurality ofwireless power receivers; acquiring control errors corresponding to afirst control error value and a second control error value from thedetected plurality of wireless power receivers, respectively; detectingtransmission parameters corresponding to the plurality of wireless powerreceivers, respectively, based on the first control error value and thesecond control error value; and transferring power in the wirelessmanner to each of the plurality of wireless power receivers by formingthe wireless power signal based on the detected transmission parameters,wherein the first control error value is received from a first wirelesspower receiver in a first time duration which is allocated to the firstwireless power receiver and the second control error value is receivedfrom a second wireless power receiver in a second time duration which isallocated to the second wireless power receiver.
 2. The method of claim1, wherein the control error corresponding to each of the plurality ofwireless power receivers is generated based on at least one of a valueobtained by subtracting an actually received amount of power from atarget amount of power corresponding to each of the plurality ofwireless power receivers, a value obtained by subtracting an actuallyreceived receiving side voltage from a target receiving side voltagecorresponding to each of the plurality of wireless power receivers, avalue obtained by subtracting an actually received receiving sidecurrent from a target receiving side current corresponding to each ofthe plurality of wireless power receivers, a value obtained bysubtracting transmission efficiency upon actually receiving power in awireless manner from a target transmission efficiency corresponding toeach of the plurality of wireless power receivers, and a value obtainedby subtracting a transmission gain upon actually receiving power in awireless manner from a target transmission gain corresponding to each ofthe plurality of wireless power receivers.
 3. The method of claim 2,wherein the transmission efficiency is a ratio between transmissionpower of the wireless power transmitter and reception powercorresponding to each of the plurality of wireless power receivers,wherein the transmission gain is a ratio between a transmitting sidevoltage corresponding to the wireless power transmitter and a receivingside voltage corresponding to each of the plurality of wireless powerreceivers, and wherein the reception power is detected based on areceiving side voltage and a receiving side current corresponding toeach of the plurality of wireless power receivers.
 4. The method ofclaim 1, wherein each of the plurality of wireless power receiverstransmits a packet to the wireless power transmitter, the packetincluding a power control message, wherein the control error istransmitted to the wireless power transmitter by being included in thepacket, the packet including the power control message, and wherein thepacket including the power control message is generated by modulatingthe wireless power signal by each of the plurality of wireless powerreceivers.
 5. The method of claim 1, wherein the transmission parameteris at least one of a frequency, an amplitude and a phase of the wirelesspower signal, and a time interval for transmission of the wireless powersignal.
 6. The method of claim 1, wherein the transmission parameter isa transmission frequency corresponding to each of the plurality ofwireless power receivers, wherein the transferring of the power in thewireless manner based on the detected transmission parameters comprises:periodically changing the frequency of the wireless power signal to atransmission frequency corresponding to each of the plurality ofwireless power receivers; and transferring power in the wireless mannerby forming the wireless power signal using the periodically changedtransmission frequency.
 7. The method of claim 1, wherein thetransferring of the power in the wireless manner based on the detectedtransmission parameters comprises: detecting an optimal transmissionparameter corresponding to the plurality of wireless power receiversbased on the detected transmission parameters; and transferring power inthe wireless manner to the plurality of wireless power receivers byforming the wireless power signal based on the optimal transmissionparameter.
 8. The method of claim 7, wherein the optimal transmissionparameter is generated by processing the detected transmissionparameters in a statistical manner.
 9. The method of claim 8, whereinthe statistical manner is a method based on at least one of an average,variance and standard deviation of the transmission parameters.
 10. Themethod of claim 1, wherein the transmission parameter is a transmissionfrequency corresponding to each of the plurality of wireless powerreceivers, wherein the transferring of the power in the wireless mannerbased on the detected transmission parameters comprises: setting aweight for each of the plurality of wireless power receivers based onthe control errors or the detected transmission parameters; setting atransmission time interval for each of the plurality of wireless powerreceivers based on the weights; and transferring power in the wirelessmanner by forming the wireless power signal having the transmissionfrequency corresponding to each of the plurality of wireless powertransmitters for the set transmission time interval.
 11. The method ofclaim 1, wherein the transmission parameters are detected based on afirst weight and a second weight proportional to the first control errorvalue and the second control error value.
 12. The method of claim 1,wherein the transmission parameter is decided as a value that thecontrol error of each of the plurality of wireless power receivers isless than a reference value.
 13. The method of claim 1, wherein thetransmission parameter is decided as a value that a control error valueof a specific wireless power receiver of the plurality of wireless powerreceivers does not increase more than a specific value.
 14. The methodof claim 1, wherein the transmission parameter is decided based on atleast one of whether or not a damage is caused on the plurality ofwireless power receivers or whether or not the plurality of wirelesspower receivers are able to wirelessly receive power from the wirelesspower transmitter.
 15. The method of claim 1, further comprisingtransmitting a control error transmission request to each of theplurality of wireless power receivers.
 16. The method of claim 15,wherein the control error transmission request is transmitted when thecontrol error is more than a reference value, when a new wireless powerreceiver is placed in a specific area, when the number of wireless powerreceivers existing in the specific area changes, when a position of atleast one wireless power receiver existing in the specific area changes,and when there is a periodically received request or a request receivedfrom the wireless power receiver, wherein the specific area is an areathrough which the wireless power signal passes or an area on which thewireless power receiver is sensed.
 17. The method of claim 1, whereineach of the plurality of wireless power receivers transmits the controlerror to the wireless power transmitter via each time slot correspondingthereto, wherein the time slot is formed by dividing a time section fortransmission of the wireless power signal by a time axis so as to beallocated to each of the plurality of wireless power receivers.
 18. Themethod of claim 17, wherein the wireless power transmitter acquires afirst control error value via a time slot corresponding to the firstwireless power receiver, so as to detect a first transmission parametercorresponding to the first wireless power receiver, wherein the wirelesspower transmitter acquires a second control error value via a time slotcorresponding to the second wireless power receiver, so as to detect asecond transmission parameter corresponding to the second wireless powerreceiver, and wherein the wireless power transmitter transfers power inthe wireless manner to the first and second wireless power receivers byforming the wireless power signal based on the first and secondtransmission parameters.
 19. A wireless power transmitter comprising: apower conversion unit configured to detect a plurality of wireless powerreceivers, receive a first control error value from a first wirelesspower receiver in a first time duration which is allocated to the firstwireless power receiver and receive a second control error value from asecond wireless power receiver in a second time duration which isallocated to the second wireless power receiver; and a controllerconfigured to acquire control errors corresponding to the first controlerror value and the second control error value from the detectedplurality of wireless power receivers, respectively, detect transmissionparameters corresponding to the plurality of wireless power receivers,respectively, based on the first control error value and the secondcontrol error value, and control the power conversion unit to transmitpower in a wireless manner to each of the plurality of wireless powerreceivers by forming the wireless power signal based on the detectedtransmission parameters.
 20. The transmitter of claim 19, wherein thecontroller sequentially acquires the control errors from the pluralityof wireless power receivers, respectively, the control errorcorresponding to each of the plurality of wireless power receivers, andwherein the controller detects the transmission parameters correspondingto the plurality of wireless power receivers, respectively, based on thesequentially acquired control errors, detects an optimal transmissionparameter corresponding to the plurality of wireless power receiversbased on the detected transmission parameters, and controls the powertransmission unit to transmit power in a wireless manner to theplurality of wireless power receivers by forming the wireless powersignal based on the optimal transmission parameter.
 21. The transmitterof claim 20, wherein the optimal transmission parameter is decided as anaverage value of the transmission parameters corresponding to theplurality of wireless power receivers, respectively.
 22. The transmitterof claim 20, wherein the control error is generated based on a valueobtained by subtracting an actually received receiving side voltage froma target receiving side voltage corresponding to each the plurality ofwireless power receivers, wherein each of the plurality of wirelesspower receivers transmits a packet to the wireless power transmitter,the packet including information related to the control error, andwherein the packet is generated by modulating the wireless power signalby each of the plurality of wireless power receivers.
 23. Thetransmitter of claim 19, wherein the controller further detectstransmission parameters based on a first weight and a second weightproportional to the first control error value and the second controlerror value.